Un sondeo espectroscópico de estrellas o galácticas

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de lectura. 03-12-2018Los catálogos de clasificaciones espectrales de estrellas masivas que recopilan sus datos de diferentes fuentes, muestran una gran disparidad en las clasificaciones que contienen. Algunas de las discrepancias se deben a las diferentes resoluciones espectrales o relaciones señal-ruido (S/N), otras a la variabilidad en las estrellas (siendo las binarias espectroscópicas las principales culpables), y otros a errores o diferencias entre los clasificadores. Para corregir esta situación, nació en 2007 la idea del sondeo espectroscópico de estrellas O Galácticas (GOSSS). GOSSS es un sondeo en el que se pretenden observar todas las estrellas O galácticas conocidas para crear la mayor base de datos espectroscópica en el azul-violeta (3900-5100 Å) de este tipo de estrellas observables visualmente ( B < 14) utilizando una resolución espectral intermedia (R ~ 2500), una alta S/N (≥ 300), y obteniendo datos de una calidad uniforme. El sondeo empezó sus observaciones partiendo inicialmente de las estrellas contenidas en la segunda versión del catálogo de estrellas O Galácticas (GOSC) y desde el comienzo del proyecto hasta la presentación de esta tesis, se han observado más de 400 noches en 4 observatorios diferentes. Como parte de esta tesis se han observado 449 estrellas dentro del programa GOSSS cuyas clasificaciones han sido incorporadas a la versión 3 de GOSC. A su vez, se ha creado un atlas de estrellas O Galácticas que ha supuesto un gran avance con respecto a los existentes debido a la calidad y uniformidad de los espectros, así como de su completitud. Algunos de los resultados notables relacionados con GOSSS son los siguientes: Se revisan los criterios de clasificación para los tipos entre O8 y B0 con indicadores más precisos que los usados en trabajos anteriores y se amplía a todas las clases de luminosidad el tipo O9.7 (anteriormente solo se clasificaban las clases mayores de III). Se introduce la nueva categoría espectral Ofc y el tipo espectral O9.2. Se introducen criterios uniformes para la definición de los fenómenos f y z. Se descubren dos nuevos miembros de la categoria Of?p y bastantes binarias espectroscópicas no detectadas hasta ahora. Todos estos elementos también han servido para afrontar estudios tan diversos como las leyes de extinción en el óptico e infrarrojo y la multiplicidad de estrellas masivas y servirán para afrontar otros como la distribución espacial de las estrellas masivas o el límite de la IMF (función de masas iniciales) en la vecindad solar. Los resultados mencionados se han publicado en los dos artículos principales que componen la base de esta tesis, que en conjunto acumulan más de 200 citas en ADS (Astrophysics Data System

YETI observations of the young transiting planet candidate CVSO 30 b

Raetz, St. et. al.CVSO 30 is a unique young low-mass system, because, for the first time, a close-in transiting and a wide directly imaged planet candidates are found around a common host star. The inner companion, CVSO 30 b, is the first possible young transiting planet orbiting a previously known weak-lined T Tauri star. With five telescopes of the 'Young Exoplanet Transit Initiative' located in Asia, Europe and South America, we monitored CVSO 30 over three years in a total of 144 nights and detected 33 fading events. In two more seasons we carried out follow-up observations with three telescopes. We can confirm that there is a change in the shape of the fading event between different observations and that the fading event even disappears and reappears. A total of 38 fading event light curves were simultaneously modelled. We derived the planetary, stellar and geometrical properties of the system and found them slightly smaller but in agreement with the values from the discovery paper. The period of the fading event was found to be 1.36 s shorter and 100 times more precise than the previous published value. If CVSO 30 b would be a giant planet on a precessing orbit, which we cannot confirm, yet, the precession period may be shorter than previously thought. But if confirmed as a planet it would be the youngest transiting planet ever detected and will provide important constraints on planet formation and migration time-scales.SR is currently a Research Fellow at ESA/ESTEC. SR, CA, RE, MK and RN would like to thank DFG for support in the Priority Programme SPP 1385 on the 'First Ten Million Years of the Solar system' in projects NE 515/34-1 and -2, NE 515/33-1 and -2, and NE 515/35-1 and -2. TK acknowledges support by the DFG program CZ 222/1-1 and RTG 1351 (extrasolar planets and their host stars). MK would like to thank Ronald Redmer and DFG in project RE 882/12-2 for financial support. MF acknowledges financial support from grants AYA2014-54348-C3-1-R and AYA2011-30147-C03-01 of the Spanish Ministry of Economy and Competivity (MINECO), co-funded with EU FEDER funds. DK and VR acknowledge support by project RD 08-81 of Shumen University. Z-YW was supported by the Chinese National Natural Science Foundation grant no. 11373033. This work was also supported by the joint fund of Astronomy of the National Nature Science Foundation of China and the Chinese Academy of Science, under Grant U1231113. XZ was supported by the Chinese National Natural Science Foundation grands no. 11073032, and by the National Basic Research Program of China (973 Program), No. 2014CB845704 and 2013CB834902. MM and CG acknowledge DFG for support in program MU2695/13-1. JS, RN and MMH would like to thank the DFG for support from the SFB-TR 7. CG, and TOBS would like to thank DFG for support in project NE 515/30-1. CM acknowledges support from the DFG through grant SCHR665/7-1. RN would like to thank the German National Science Foundation (Deutsche Forschungsgemeinschaft, DFG) for general support in various projects. We would like to acknowledge financial support from the Thuringian government (B 515-07010) for the STK CCD camera used in this project. This work has been supported by a VEGA Grant 2/0143/13 of the Slovak Academy of Sciences. The observations obtained with the MPG 2.2 m telescope were supported by the Ministry of Education, Youth and Sports project - LG14013 (Tycho Brahe: Supporting Ground-based Astronomical Observations). We would like to thank the observers S. Ehlerova and A. Kawka for obtaining the data.Peer reviewe

Polarized blazar X-rays imply particle acceleration in shocks

Full list of authors: Liodakis, Ioannis; Marscher, Alan P.; Agudo, Ivan; Berdyugin, Andrei V.; Bernardos, Maria I.; Bonnoli, Giacomo; Borman, George A.; Casadio, Carolina; Casanova, Victor; Cavazzuti, Elisabetta; Cavero, Nicole Rodriguez; Di Gesu, Laura; Di Lalla, Niccolo; Donnarumma, Immacolata; Ehlert, Steven R.; Errando, Manel; Escudero, Juan; Garcia-Comas, Maya; Agis-Gonzalez, Beatriz; Husillos, Cesar; Jormanainen, Jenni; Jorstad, Svetlana G.; Kagitani, Masato; Kopatskaya, Evgenia N.; Kravtsov, Vadim; Krawczynski, Henric; Lindfors, Elina; Larionova, Elena G.; Madejski, Grzegorz M.; Marin, Frederic; Marchini, Alessandro; Marshall, Herman L.; Morozova, Daria A.; Massaro, Francesco; Masiero, Joseph R.; Mawet, Dimitri; Middei, Riccardo; Millar-Blanchaer, Maxwell A.; Myserlis, Ioannis; Negro, Michela; Nilsson, Kari; O'Dell, Stephen L.; Omodei, Nicola; Pacciani, Luigi; Paggi, Alessandro; Panopoulou, Georgia V.; Peirson, Abel L.; Perri, Matteo; Petrucci, Pierre-Olivier; Poutanen, Juri; Puccetti, Simonetta; Romani, Roger W.; Sakanoi, Takeshi; Savchenko, Sergey S.; Sota, Alfredo; Tavecchio, Fabrizio; Tinyanont, Samaporn; Vasilyev, Andrey A.; Weaver, Zachary R.; Zhovtan, Alexey V.; Antonelli, Lucio A.; Bachetti, Matteo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo; Bianchi, Stefano; Bongiorno, Stephen D.; Bonino, Raffaella; Brez, Alessandro; Bucciantini, Niccolo; Capitanio, Fiamma; Castellano, Simone; Ciprini, Stefano; Costa, Enrico; De Rosa, Alessandra; Del Monte, Ettore; Di Marco, Alessandro; Doroshenko, Victor; Dovciak, Michal; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli, Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi; Heyl, Jeremy; Iwakiri, Wataru; Karas, Vladimir; Kitaguchi, Takao; Kolodziejczak, Jeffery J.; La Monaca, Fabio; Latronico, Luca; Maldera, Simone; Manfreda, Alberto; Marinucci, Andrea; Matt, Giorgio; Mitsuishi, Ikuyuki; Mizuno, Tsunefumi; Muleri, Fabio; Ng, Stephen C. -Y.; Oppedisano, Chiara; Papitto, Alessandro; Pavlov, George G.; Pesce-Rollins, Melissa; Pilia, Maura; Possenti, Andrea; Ramsey, Brian D.; Rankin, John; Ratheesh, Ajay; Sgro, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre, Gloria; Tamagawa, Toru; Taverna, Roberto; Tawara, Yuzuru; Tennant, Allyn F.; Thomas, Nicolas E.; Tombesi, Francesco; Trois, Alessio; Tsygankov, Sergey; Turolla, Roberto; Vink, Jacco; Weisskopf, Martin C.; Wu, Kinwah; Xie, Fei; Zane, Silvia.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier1,2,3, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree ΠX of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock. © The Author(s) 2022.I.L. was supported by the JSPS postdoctoral short-term fellowship programme. The Imaging X-ray Polarimetry Explorer (IXPE) is a joint US and Italian mission. The US contribution is supported by the National Aeronautics and Space Administration (NASA) and led and managed by its Marshall Space Flight Center (MSFC), with industry partner Ball Aerospace (contract NNM15AA18C). The Italian contribution is supported by the Italian Space Agency (Agenzia Spaziale Italiana, ASI) through contract ASI-OHBI-2017-12-I.0, agreements ASI-INAF-2017-12-H0 and ASI-INFN-2017.13-H0, and its Space Science Data Center (SSDC) with agreements ASI-INAF-2022-14-HH.0 and ASI-INFN 2021-43-HH.0, and by the Istituto Nazionale di Astrofisica (INAF) and the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. This research used data products provided by the IXPE Team (MSFC, SSDC, INAF and INFN) and distributed with additional software tools by the High-Energy Astrophysics Science Archive Research Center (HEASARC), at NASA Goddard Space Flight Center (GSFC). Data from the Steward Observatory spectropolarimetric monitoring project were used. This programme is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, NNX12AO93G and NNX15AU81G. This research has made use of data from the RoboPol programme, a collaboration between Caltech, the University of Crete, the Institute of Astrophysics-Foundation for Research and Technology (IA-FORTH), the Inter-University Centre for Astronomy and Astrophysics (IUCAA), the Max Planck Institute for Radioastronomy (MPIfR) and the Nicolaus Copernicus University, which was conducted at Skinakas Observatory in Crete, Greece. The Instituto Astrofísica Andalucía (IAA)-Consejo Superior de Investigaciones Científicas (CSIC) co-authors acknowledge financial support from the Spanish Ministerio de Ciencia e Innovacion (MCINN) through the ‘Center of Excellence Severo Ochoa‘ award for the Instituto de Astrofisica de Andalucia-CSIC (SEV-2017-0709). Acquisition and reduction of the POLAMI and Monitoring AGN with Polarimetry at the Calar Alto Telescopes (MAPCAT) data were supported in part by Ministerio de Ciencia e Innovación (MICINN) through grants AYA2016-80889-P and PID2019-107847RB-C44. The POLAMI observations were carried out at the IRAM 30 m Telescope. IRAM is supported by the National Institute of Sciences of the Universe (INSU)/Scientific Research National Center (CNRS) (France), Max-Planck-Gesellschaft (MPG) (Germany) and Instituto Geográfico Nacional (IGN) (Spain). The research at Boston University was supported in part by National Science Foundation grant AST-2108622, NASA Fermi Guest Investigator grant 80NSSC21K1917 and NASA Swift Guest Investigator grant 80NSSC22K0537. This study uses observations conducted with the 1.8 m Perkins Telescope Observatory in Arizona (USA), which is owned and operated by Boston University. Based on observations obtained at the Hale Telescope, Palomar Observatory as part of a continuing collaboration between the California Institute of Technology, NASA/Jet Propulsion Laboratory (JPL), Yale University and the National Astronomical Observatories of China. This research made use of Photutils, an Astropy package for detection and photometry of astronomical sources60. G.V.P. acknowledges support by NASA through the NASA Hubble Fellowship grant no. HST-HF2-51444.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. Based on observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained (in part) with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and the Nordic Optical Telescope. V.K. thanks the Vilho, Yrjö and Kalle Väisälä Foundation. J.J. was supported by Academy of Finland project 320085. E.L. was supported by Academy of Finland projects 317636 and 320045. Part of the French contribution was supported by the CNRS and the French spatial agency (CNES). Based on observations collected at the Observatorio de Sierra Nevada, owned and operated by the Instituto de Astrofisica de Andalucia (IAA-CSIC). Based on observations collected at the Centro Astronomico Hispano-Aleman (CAHA), proposal 22A-2.2-015, operated jointly by Junta de Andalucia and Consejo Superior de Investigaciones Cientificas (IAA-CSIC).Peer reviewe

X-Ray Polarization Observations of BL Lacertae

Full list of authors: Middei, Riccardo; Liodakis, Ioannis; Perri, Matteo; Puccetti, Simonetta; Cavazzuti, Elisabetta; Di Gesu, Laura; Ehlert, Steven R.; Madejski, Grzegorz; Marscher, Alan P.; Marshall, Herman L.; Muleri, Fabio; Negro, Michela; Jorstad, Svetlana G.; Agis-Gonzalez, Beatriz; Agudo, Ivan; Bonnoli, Giacomo; Bernardos, Maria, I; Casanova, Victor; Garcia-Comas, Maya; Husillos, Cesar; Marchini, Alessandro; Sota, Alfredo; Kouch, Pouya M.; Lindfors, Elina; Borman, George A.; Kopatskaya, Evgenia N.; Larionova, Elena G.; Morozova, Daria A.; Savchenko, Sergey S.; Vasilyev, Andrey A.; Zhovtan, Alexey, V; Casadio, Carolina; Escudero, Juan; Myserlis, Ioannis; Hales, Antonio; Kameno, Seiji; Kneissl, Ruediger; Messias, Hugo; Nagai, Hiroshi; Blinov, Dmitry; Bourbah, Ioakeim G.; Kiehlmann, Sebastian; Kontopodis, Evangelos; Mandarakas, Nikos; Romanopoulos, Stylianos; Skalidis, Raphael; Vervelaki, Anna; Masiero, Joseph R.; Mawet, Dimitri; Millar-Blanchaer, Maxwell A.; Panopoulou, Georgia, V; Tinyanont, Samaporn; Berdyugin, Andrei, V; Kagitani, Masato; Kravtsov, Vadim; Sakanoi, Takeshi; Imazawa, Ryo; Sasada, Mahito; Fukazawa, Yasushi; Kawabata, Koji S.; Uemura, Makoto; Mizuno, Tsunefumi; Nakaoka, Tatsuya; Akitaya, Hiroshi; Gurwell, Mark; Rao, Ramprasad; Di Lalla, Niccolo; Cibrario, Nicolo; Donnarumma, Immacolata; Kim, Dawoon E.; Omodei, Nicola; Pacciani, Luigi; Poutanen, Juri; Tavecchio, Fabrizio; Antonelli, Lucio A.; Bachetti, Matteo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo; Bianchi, Stefano; Bongiorno, Stephen D.; Bonino, Raffaella; Brez, Alessandro; Bucciantini, Niccolo; Capitanio, Fiamma; Castellano, Simone; Ciprini, Stefano; Costa, Enrico; De Rosa, Alessandra; Del Monte, Ettore; Di Marco, Alessandro; Doroshenko, Victor; Dovciak, Michal; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli, Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi; Heyl, Jeremy; Iwakiri, Wataru; Karas, Vladimir; Kitaguchi, Takao; Kolodziejczak, Jeffery J.; Krawczynski, Henric; La Monaca, Fabio; Latronico, Luca; Maldera, Simone; Manfreda, Alberto; Marin, Frederic; Marinucci, Andrea; Massaro, Francesco; Matt, Giorgio; Mitsuishi, Ikuyuki; Ng, C-Y; O'Dell, Stephen L.; Oppedisano, Chiara; Papitto, Alessandro; Pavlov, George G.; Peirson, Abel L.; Pesce-Rollins, Melissa; Petrucci, Pierre-Olivier; Pilia, Maura; Possenti, Andrea; Ramsey, Brian D.; Rankin, John; Ratheesh, Ajay; Romani, Roger W.; Sgro, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre, Gloria; Tamagawa, Toru; Taverna, Roberto; Tawara, Yuzuru; Tennant, Allyn F.; Thomas, Nicholas E.; Tombesi, Francesco; Trois, Alessio; Tsygankov, Sergey; Turolla, Roberto; Vink, Jacco; Weisskopf, Martin C.; Wu, Kinwah; Xie, Fei; Zane, Silvia.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus that the synchrotron emission is responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae (BL Lac) performed with the Imaging X-ray Polarimetry Explorer, from which an upper limit to the polarization degree ΠX < 12.6% was found in the 2–8 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton-synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac. © 2022. The Author(s). Published by the American Astronomical Society.The Imaging X-ray Polarimetry Explorer (IXPE) is a joint US and Italian mission. The US contribution is supported by the National Aeronautics and Space Administration (NASA) and led and managed by its Marshall Space Flight Center (MSFC), with industry partner Ball Aerospace (contract NNM15AA18C). The Italian contribution is supported by the Italian Space Agency (Agenzia Spaziale Italiana, ASI) through contract ASI-OHBI-2017-12-I.0, agreements ASI-INAF-2017-12-H0 and ASI-INFN-2017.13-H0, and its Space Science Data Center (SSDC), and by the Istituto Nazionale di Astrofisica (INAF) and the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. This research used data products provided by the IXPE Team (MSFC, SSDC, INAF, and INFN) and distributed with additional software tools by the High-Energy Astrophysics Science Archive Research Center (HEASARC), at NASA Goddard Space Flight Center (GSFC). We acknowledge financial support from ASI-INAF agreement n. 2022-14-HH.0. The research at Boston University was supported in part by National Science Foundation grant AST-2108622 and NASA Swift Guest Investigator grant 80NSSC22K0537. This research has made use of data from the RoboPol program, a collaboration between Caltech, the University of Crete, IA-FORTH, IUCAA, the MPIfR, and the Nicolaus Copernicus University, which was conducted at Skinakas Observatory in Crete, Greece. The IAA-CSIC coauthors acknowledge financial support from the Spanish "Ministerio de Ciencia e Innovacion" (MCINN) through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofísica de Andalucía-CSIC (SEV-2017-0709). Acquisition and reduction of the POLAMI, TOP-MAPCAR, and OSN data was supported in part by MICINN through grants AYA2016-80889-P and PID2019-107847RB-C44. The POLAMI observations were carried out at the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). This Letter makes use of the following ALMA director's discretionary time data under proposal ESO#2021.A.00016.T. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada), MOST, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. Some of the data reported here are based on observations obtained at the Hale Telescope, Palomar Observatory as part of a continuing collaboration between the California Institute of Technology, NASA/JPL, Yale University, and the National Astronomical Observatories of China. This research made use of Photutils, an Astropy package for detection and photometry of astronomical sources (Bradley et al. 2019). G.V.P. acknowledges support by NASA through the NASA Hubble Fellowship grant #HST-HF2-51444.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. The data in this study include observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku, and the University of Oslo, representing Denmark, Finland, and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofísica de Andalucía (IAA) under a joint agreement with the University of Copenhagen and NOT. E.L. was supported by Academy of Finland projects 317636 and 320045. Part of the French contribution is supported by the Scientific Research National Center (CNRS) and the French Spatial Agency (CNES). Some of the data are based on observations collected at the Observatorio de Sierra Nevada, owned and operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC). Further data are based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA), operated jointly by Junta de Andalucía and Consejo Superior de Investigaciones Científicas (IAA-CSIC). D.B., S.K., R.S., and N. M. acknowledge support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program under grant agreement No. 771282. C.C. acknowledges support by the European Research Council (ERC) under the HORIZON ERC Grants 2021 program under grant agreement No. 101040021. The Dipol-2 polarimeter was built in cooperation by the University of Turku, Finland, and the Leibniz Institut für Sonnenphysik, Germany, with support from the Leibniz Association grant SAW-2011-KIS-7. We are grateful to the Institute for Astronomy, University of Hawaii, for the allocated observing time. A.H. acknowledges The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work was supported by JST, the establishment of university fellowships toward the creation of science technology innovation; grant No. JPMJFS2129. This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant Nos. JP21H01137. This work was also partially supported by Optical and Near-Infrared Astronomy Inter-University Cooperation Program from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).Peer reviewe

X-Ray Polarization of BL Lacertae in Outburst

Full list of authors: Peirson, Abel L.; Negro, Michela; Liodakis, Ioannis; Middei, Riccardo; Kim, Dawoon E.; Marscher, Alan P.; Marshall, Herman L.; Pacciani, Luigi; Romani, Roger W.; Wu, Kinwah; Di Marco, Alessandro; Di Lalla, Niccolo; Omodei, Nicola; Jorstad, Svetlana G.; Agudo, Ivan; Kouch, Pouya M.; Lindfors, Elina; Aceituno, Francisco Jose; Bernardos, Maria I.; Bonnoli, Giacomo; Casanova, Victor; Garcia-Comas, Maya; Agis-Gonzalez, Beatriz; Husillos, Cesar; Marchini, Alessandro; Sota, Alfredo; Casadio, Carolina; Escudero, Juan; Myserlis, Ioannis; Sievers, Albrecht; Gurwell, Mark; Rao, Ramprasad; Imazawa, Ryo; Sasada, Mahito; Fukazawa, Yasushi; Kawabata, Koji S.; Uemura, Makoto; Mizuno, Tsunefumi; Nakaoka, Tatsuya; Akitaya, Hiroshi; Cheong, Yeon; Jeong, Hyeon-Woo; Kang, Sincheol; Kim, Sang-Hyun; Lee, Sang-Sung; Angelakis, Emmanouil; Kraus, Alexander; Cibrario, Nicolo; Donnarumma, Immacolata; Poutanen, Juri; Tavecchio, Fabrizio; Antonelli, Lucio A.; Bachetti, Matteo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo; Bianchi, Stefano; Bongiorno, Stephen D.; Bonino, Raffaella; Brez, Alessandro; Bucciantini, Niccolo; Capitanio, Fiamma; Castellano, Simone; Cavazzuti, Elisabetta; Chen, Chien-Ting; Ciprini, Stefano; Costa, Enrico; De Rosa, Alessandra; Del Monte, Ettore; Di Gesu, Laura; Doroshenko, Victor; Dovciak, Michal; Ehlert, Steven R.; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli, Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi; Heyl, Jeremy; Iwakiri, Wataru; Kaaret, Philip; Karas, Vladimir; Kitaguchi, Takao; Kolodziejczak, Jeffery J.; Krawczynski, Henric; La Monaca, Fabio; Latronico, Luca; Madejski, Grzegorz; Maldera, Simone; Manfreda, Alberto; Marin, Frederic; Marinucci, Andrea; Massaro, Francesco; Matt, Giorgio; Mitsuishi, Ikuyuki; Muleri, Fabio; Ng, C. -Y.; O'Dell, Stephen L.; Oppedisano, Chiara; Papitto, Alessandro; Pavlov, George G.; Perri, Matteo; Pesce-Rollins, Melissa; Petrucci, Pierre-Olivier; Pilia, Maura; Possenti, Andrea; Puccetti, Simonetta; Ramsey, Brian D.; Rankin, John; Ratheesh, Ajay; Roberts, Oliver J.; Sgro, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre, Gloria; Swartz, Douglas A.; Tamagawa, Toru; Taverna, Roberto; Tawara, Yuzuru; Tennant, Allyn F.; Thomas, Nicholas E.; Tombesi, Francesco; Trois, Alessio; Tsygankov, Sergey; Turolla, Roberto; Vink, Jacco; Weisskopf, Martin C.; Xie, Fei; Zane, Silvia.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.We report the first >99% confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/γ-ray outburst, a 287 ks observation (2022 November 27–30) was taken using the Imaging X-ray Polarimetry Explorer (IXPE), together with contemporaneous multiwavelength observations from the Neil Gehrels Swift observatory and XMM-Newton in soft X-rays (0.3–10 keV), NuSTAR in hard X-rays (3–70 keV), and optical polarization from the Calar Alto and Perkins Telescope observatories. Our contemporaneous X-ray data suggest that the IXPE energy band is at the crossover between the low- and high-frequency blazar emission humps. The source displays significant variability during the observation, and we measure polarization in three separate time bins. Contemporaneous X-ray spectra allow us to determine the relative contribution from each emission hump. We find >99% confidence X-ray polarization {{\rm{\Pi }}}_{2\mbox{--}4\mathrm{keV}}={21.7}_{-7.9}^{+5.6} \% and electric vector polarization angle ψ2–4keV = −28fdg7 ± 8fdg7 in the time bin with highest estimated synchrotron flux contribution. We discuss possible implications of our observations, including previous IXPE BL Lacertae pointings, tentatively concluding that synchrotron self-Compton emission dominates over hadronic emission processes during the observed epochs. © 2023. The Author(s). Published by the American Astronomical Society.The Imaging X-ray Polarimetry Explorer (IXPE) is a joint US and Italian mission. The US contribution is supported by the National Aeronautics and Space Administration (NASA) and led and managed by its Marshall Space Flight Center (MSFC), with industry partner Ball Aerospace (contract NNM15AA18C). The Italian contribution is supported by the Italian Space Agency (Agenzia Spaziale Italiana, ASI) through contract ASI-OHBI-2017-12-I.0, agreements ASI-INAF-2017-12-H0 and ASI-INFN-2017.13-H0, and its Space Science Data Center (SSDC) with agreements ASI-INAF-2022-14-HH.0 and ASI-INFN 2021-43-HH.0, and by the Istituto Nazionale di Astrofisica (INAF) and the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. This research used data products provided by the IXPE Team (MSFC, SSDC, INAF, and INFN) and distributed with additional software tools by the High-Energy Astrophysics Science Archive Research Center (HEASARC), at NASA Goddard Space Flight Center (GSFC). Funding for this work was provided in part by contract 80MSFC17C0012 from the MSFC to MIT in support of the IXPE project. Support for this work was provided in part by the NASA through the Smithsonian Astrophysical Observatory (SAO) contract SV3-73016 to MIT for support of the Chandra X-Ray Center (CXC), which is operated by SAO for and on behalf of NASA under contract NAS8-03060. The IAA-CSIC coauthors acknowledge financial support from the Spanish "Ministerio de Ciencia e Innovación" (MCIN/AEI/10.13039/501100011033) through the Center of Excellence Severo Ochoa award for the Instituto de Astrofíisica de Andalucía-CSIC (CEX2021-001131-S), and through grants PID2019-107847RB-C44 and PID2022-139117NB-C44. Some of the data are based on observations collected at the Observatorio de Sierra Nevada, owned and operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC). Further data are based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA), operated jointly by Junta de Andalucía and Consejo Superior de Investigaciones Científicas (IAA-CSIC). The POLAMI observations were carried out at the IRAM 30 m Telescope. I.R.A.M. is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The Submillimetre Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Maunakea, the location of the SMA, is a culturally important site for the indigenous Hawaiian people; we are privileged to study the cosmos from its summit. The data in this study include observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku, and the University of Oslo, representing Denmark, Finland, and Norway, the University of Iceland, and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofísica de Andalucía (IAA) under a joint agreement with the University of Copenhagen and NOT. E.L. was supported by Academy of Finland projects 317636 and 320045. We acknowledge funding to support our NOT observations from the Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Finland (Academy of Finland grant nr 306531). The research at Boston University was supported in part by National Science Foundation grant AST-2108622, NASA Fermi Guest Investigator grants 80NSSC21K1917 and 80NSSC22K1571, and NASA Swift Guest Investigator grant 80NSSC22K0537. This study used observations conducted with the 1.8 m Perkins Telescope Observatory (PTO) in Arizona (USA), which is owned and operated by Boston University. The above study is based in part on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. We are grateful to the NuSTAR team for approving our DDT request. This work was supported under NASA contract No. NNG08FD60C, and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the NASA. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). This work was supported by JST, the establishment of university fellowships toward the creation of science technology innovation, grant No. JPMJFS2129. This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant No. JP21H01137. This work was also partially supported by Optical and Near-Infrared Astronomy Inter-University Cooperation Program from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan. We are grateful to the observation and operating members of Kanata Telescope. M.N. acknowledges the support by NASA under award number 80GSFC21M0002. C.C. acknowledges support by the ERC under the Horizon ERC Grants 2021 program under grant agreement no. 101040021. S.K., S.-S.L., W.Y.C., S.-H.K., and H.-W.J. were supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MIST; 2020R1A2C2009003). The KVN is a facility operated by the Korea Astronomy and Space Science Institute. The KVN operations are supported by KREONET (Korea Research Environment Open NETwork), which is managed and operated by KISTI (Korea Institute of Science and Technology Information). Partly based on observations with the 100 m telescope of the MPIfR (Max-Planck-Institut für Radioastronomie) at Effelsberg. Observations with the 100 m radio telescope at Effelsberg have received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 101004719 (ORP). A.L.P. acknowledges support from NASA FINESST grant 80NSSC19K1407 and the Stanford Data Science Scholars program.Peer reviewe

Young Exoplanet Transit Initiative follow-up observations of the T Tauri star CVSO 30 with transit-like dips

The T Tauri star CVSO 30, also known as PTFO 8-8695, was studied intensively with ground-based telescopes as well as with satellites over the last decade. It showed a variable light curve with additional repeating planetary transit-like dips every ∼10.8 h. However, these dimming events changed in depth and duration since their discovery and from autumn 2018 on, they were not even present or near the predicted observing times. As reason for the detected dips and their changes within the complex light curve, e.g. a disintegrating planet, a circumstellar dust clump, stellar spots, possible multiplicity, and orbiting clouds at a Keplerian co-rotating radius were discussed and are still under debate. In this paper, we present additional optical monitoring of CVSO 30 with the meter class telescopes of the Young Exoplanet Transit Initiative in Asia and Europe over the last 7 yr and characterize CVSO 30 with the new Early Data Release 3 of the European Space Agency-Gaia mission. As a result, we describe the evolution of the dimming events in the optical wavelength range since 2014 and present explanatory approaches for the observed variabilities. We conclude that orbiting clouds of gas at a Keplerian co-rotating radius are the most promising scenario to explain most changes in CVSO 30’s light curve. © 2022 The Author(s).This work is based on observations obtained with telescopes of the University Observatory Jena, operated by the Astrophysical Institute of the Friedrich-Schiller-Universität Jena. We thank B. Baghdasaryan, N. Belko, S. Buder, M. Dadalauri, M. Geymeier, H. Gilbert, A. Gonzalez, F. Hildebrandt, H. Keppler, O. Lux, S. Masda, P. Protte, J. Trautmann, A. Trepanowski, and S. Schlagenhauf, who have been involved in some observations of this project, obtained at the University Observatory Jena. This research was partly based on data obtained at the 1.5 m telescope of the Sierra Nevada Observatory (Spain), which is operated by the Consejo Superior de Investigaciones Científicas (CSIC) through the Instituto de Astrofísica de Andalucía. We thank J.F. Aceituno and V. Casanova for their help with the observations. This publication is partly based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 090.C-0448(A). RB, RN, and MM acknowledge the support of the DFG priority programme SPP 1992 ‘Exploring the Diversity of Extrasolar Planets’ in projects NE 515/58-1 and MU 2695/27-1. We acknowledge financial support from the Spanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Innovación y Universidades and the ERDF through projects PID2019-109522GB-C52 and AYA2016-79425-C3-3-P, and the Centre of Excellence ‘Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). We thank R. Errmann for developing and providing the photometry routine ‘AUTOMAT.PY’ and also C. Broeg for his program ‘PHOTOMETRY’. This publication makes use of data products of the SIMBAD and VizieR data bases, operated at CDS, Strasbourg, France. We also thank the Gaia Data Processing and Analysis Consortium of the ESA for processing and providing the data of the Gaia mission. We thank the MAST portal for providing the TESS photometric results and the MESA Isochrones & Stellar Tracks website for the bolometric correction tables.Peer reviewe

Discovery and mass measurement of the hot, transiting, Earth-sized planet, GJ 3929 b

Full list of authors: Kemmer, J.; Dreizler, S.; Kossakowski, D.; Stock, S.; Quirrenbach, A.; Caballero, J. A.; Amado, P. J.; Collins, K. A.; Espinoza, N.; Herrero, E.; Jenkins, J. M.; Latham, D. W.; Lillo-Box, J.; Narita, N.; Pallé, E.; Reiners, A.; Ribas, I.; Ricker, G.; Rodríguez, E.; Seager, S.; Vanderspek, R.; Wells, R.; Winn, J.; Aceituno, F. J.; Béjar, V. J. S.; Barclay, T.; Bluhm, P.; Chaturvedi, P.; Cifuentes, C.; Collins, K. I.; Cortés-Contreras, M.; Demory, B. -O.; Fausnaugh, M. M.; Fukui, A.; Gómez Maqueo Chew, Y.; Galadí-Enríquez, D.; Gan, T.; Gillon, M.; Golovin, A.; Hatzes, A. P.; Henning, Th.; Huang, C.; Jeffers, S. V.; Kaminski, A.; Kunimoto, M.; Kürster, M.; López-González, M. J.; Lafarga, M.; Luque, R.; McCormac, J.; Molaverdikhani, K.; Montes, D.; Morales, J. C.; Passegger, V. M.; Reffert, S.; Sabin, L.; Schöfer, P.; Schanche, N.; Schlecker, M.; Schroffenegger, U.; Schwarz, R. P.; Schweitzer, A.; Sota, A.; Tenenbaum, P.; Trifonov, T.; Vanaverbeke, S.; Zechmeister, M.We report the discovery of GJ 3929 b, a hot Earth-sized planet orbiting the nearby M3.5 V dwarf star, GJ 3929 (G 180-18, TOI-2013). Joint modelling of photometric observations from TESS sectors 24 and 25 together with 73 spectroscopic observations from CARMENES and follow-up transit observations from SAINT-EX, LCOGT, and OSN yields a planet radius of Rb = 1.150 ± 0.040 R⊕, a mass of Mb = 1.21 ± 0.42 M⊕, and an orbital period of Pb = 2.6162745 ± 0.0000030 d. The resulting density of ρb = 4.4 ± 1.6 g cm−3 is compatible with the Earth’s mean density of about 5.5 g cm−3. Due to the apparent brightness of the host star (J = 8.7 mag) and its small size, GJ 3929 b is a promising target for atmospheric characterisation with the JWST. Additionally, the radial velocity data show evidence for another planet candidate with P[c] = 14.303 ± 0.035 d, which is likely unrelated to the stellar rotation period, Prot = 122 ± 13 d, which we determined from archival HATNet and ASAS-SN photometry combined with newly obtained TJO data. © ESO 2022.This paper is based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory. This work includes observationscarried out at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (OAN-SPM), Baja California, México. We acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia, Innovación y Universidades and the ERDF through projects PID2019-109522GB-C5[1:4], PID2019-107061GB-C64, PID2019-110689RB-100, ESP2017-87676-C5-1-R, and the Centre of Excellence “Severo Ochoa” and “María de Maeztu” awards to the Instituto de Astrofísica de Canarias (CEX2019-000920-S), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Centro de Astrobiología (MDM-2017-0737), the Swiss National Science Foundation (PP00P2-163967 and PP00P2-190080), the Centre for Space and Habitability of the University of Bern, the National Centre for Competence in Research PlanetS, supported by the Swiss National Science Foundation, the Deutsche Forschungsgemeinschaft priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (JE 701/5-1), the Excellence Cluster ORIGINS, which is funded by the Deutsche Forschungsgemeinschaft under Germany’s Excellence Strategy (EXC-2094 – 390783311), NASA (NNX17AG24G), JSPS KAKENHI Grant Number JP18H05439, JST CREST Grant Number JPMJCR1761, the Astrobiology Center of National Institutes of Natural Sciences (NINS) (Grant Number AB031010), the UNAM-DGAPA PAPIIT (BG-101321), the “la Caixa” Foundation (100010434), the European Union Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie (No. 847648, fellowship code LCF/BQ/PI20/11760023), and the Generalitat de Catalunya/CERCA programme. Data were partly collected with the 90-cm telescope at Observatorio de Sierra Nevada (OSN), operated by the Instituto de Astrofísica de Andalucí a (IAA, CSIC). We deeply acknowledge the OSN telescope operators for their very appreciable support.Peer reviewe

A Newtonian Model for the WASP-148 Exoplanetary System Enhanced with TESS and Ground-based Photometric Observations

The WASP-148 planetary system has a rare architecture with a transiting Saturn-mass planet on a tight orbit which is accompanied by a slightly more massive planet on a nearby outer orbit. Using new space-born photometry and ground-based follow-up transit observations and data available in literature, we performed modeling that accounts for gravitational interactions between both planets. Thanks to the new transit timing data for planet b, uncertainties of orbital periods and eccentricities for both planets were reduced relative to previously published values by a factor of 3-4. Variation in transit timing has an amplitude of about 20 min and can be easily followed-up with a 1-m class telescopes from the ground. An approximated transit ephemeris, which accounts for gravitational interactions with an accuracy up to 5 min, is provided. No signature of transits was found for planet c down to the Neptune-size regime. No other transiting companions were found down to a size of about 2.4 Earth radii for interior orbits. We notice, however, that the regime of terrestrial-size planets still remains unexplored in that system. © 2020 Copernicus Foundation for Polish Astronomy. All rights reserved.GM acknowledges the financial support from the National Science Centre, Poland through grant no. 2016/23/B/ST9/00579. MF acknowledges financial support from grant AYA2016-79425-C3-3-P of the Spanish Ministry of Economy and Competitiveness (MINECO), co-funded with EU FEDER funds, and grant PID2019-109522GB-C5X/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation (MICINN). This paper includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). MF, AS, and AGS acknowledge financial support from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This research made use of Lightkurve, a Python package for Kepler and TESS data analysis (Lightkurve Collaboration, 2018). This research has made use of the SIMBAD database and the VizieR catalogue access tool, operated at CDS, Strasbourg, France, and NASA's Astrophysics Data System Bibliographic Services.Peer reviewe

New massive members of Cygnus OB2

Context. The Cygnus complex is one of the most powerful star forming regions at a close distance from the Sun (~1.4 kpc). Its richest OB association Cygnus OB2 is known to harbor many tens of O-type stars and hundreds of B-type stars, providing a large homogeneous population of OB stars that can be analyzed. Many studies of its massive population have been developed in the last decades, although the total number of OB stars is still incomplete. Aim. Our aim is to increase the sample of O and B members of Cygnus OB2 and its surroundings by spectroscopically classifying 61 candidates as possible OB-type members of Cygnus OB2, using new intermediate resolution spectroscopy. Methods. We have obtained intermediate resolution (R ~ 5000) spectra for all of the OB-type candidates between 2013 and 2017. We thus performed a spectral classification of the sample using HeI-II and metal lines rates, as well as the Marxist Ghost Buster (MGB) software for O-type stars and the IACOB standards catalog for B-type stars. Results. From the whole sample of 61 candidates, we have classified 42 stars as new massive OB-type stars, earlier than B3, in Cygnus OB2 and surroundings, including 11 O-type stars. The other candidates are discarded as they display later spectral types inconsistent with membership in the association. We have also obtained visual extinctions for all the new confirmed massive OB members, placing them in a Hertzsprung-Russell Diagram using calibrations for T and luminosity. Finally, we have studied the age and extinction distribution of our sample within the region. Conclusions. We have obtained new blue intermediate-resolution spectra suitable for spectral classification of 61 OB candidates in Cygnus OB2 and surroundings. The confirmation of 42 new OB massive stars (earlier than B3) in the region allows us to increase the young massive population known in the field. We have also confirmed the correlation between age and Galactic longitude previously found in the region. We conclude that many O and early B stars at B > 16 mag are still undiscovered in Cygnus.© ESO 2018.We acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2012-39364-C02-01, AYA 2015-68012-C2-01 and Severo Ochoa SEV-2015-0548. A.S. also acknowledges support from MINECO through grants AYA2013-40 611-P and AYA2016-75 931-C2-2-P. AP and CBM acknowledge support from the Sonderforschungsbereich SFB 881 “The Milky Way System” (subproject B5) of the German Research Foundation (DFG).Peer Reviewe