Discovery of X-ray polarization angle rotation in the jet from blazar Mrk 421

Full list of the authors: Di Gesu, Laura; Marshall, Herman L.; Ehlert, Steven R.; Kim, Dawoon E.; Donnarumma, Immacolata; Tavecchio, Fabrizio; Liodakis, Ioannis; Kiehlmann, Sebastian; Agudo, Iván; Jorstad, Svetlana G.; Muleri, Fabio; Marscher, Alan P.; Puccetti, Simonetta; Middei, Riccardo; Perri, Matteo; Pacciani, Luigi; Negro, Michela; Romani, Roger W.; Di Marco, Alessandro; Blinov, Dmitry; Bourbah, Ioakeim G.; Kontopodis, Evangelos; Mandarakas, Nikos; Romanopoulos, Stylianos; Skalidis, Raphael; Vervelaki, Anna; Casadio, Carolina; Escudero, Juan; Myserlis, Ioannis; Gurwell, Mark A.; Rao, Ramprasad; Keating, Garrett K.; Kouch, Pouya M.; Lindfors, Elina; Aceituno, Francisco José; Bernardos, Maria I.; Bonnoli, Giacomo; Casanova, Víctor; García-Comas, Maya; Agís-González, Beatriz; Husillos, César; Marchini, Alessandro; Sota, Alfredo; Imazawa, Ryo; Sasada, Mahito; Fukazawa, Yasushi; Kawabata, Koji S.; Uemura, Makoto; Mizuno, Tsunefumi; Nakaoka, Tatsuya; Akitaya, Hiroshi; Savchenko, Sergey S.; Vasilyev, Andrey A.; Gómez, José L.; Antonelli, Lucio A.; Barnouin, Thibault; Bonino, Raffaella; Cavazzuti, Elisabetta; Costamante, Luigi; Chen, Chien-Ting; Cibrario, Nicolò; De Rosa, Alessandra; Di Pierro, Federico; Errando, Manel; Kaaret, Philip; Karas, Vladimir; Krawczynski, Henric; Lisalda, Lindsey; Madejski, Grzegorz; Malacaria, Christian; Marin, Frédéric; Marinucci, Andrea; Massaro, Francesco; Matt, Giorgio; Mitsuishi, Ikuyuki; O'Dell, Stephen L.; Paggi, Alessandro; Peirson, Abel L.; Petrucci, Pierre-Olivier; Ramsey, Brian D.; Tennant, Allyn F.; Wu, Kinwah; Bachetti, Matteo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo; Bianchi, Stefano; Bongiorno, Stephen D.; Brez, Alessandro; Bucciantini, Niccolò; Capitanio, Fiamma; Castellano, Simone; Ciprini, Stefano; Costa, Enrico; Del Monte, Ettore; Di Lalla, Niccolò; Doroshenko, Victor; Dovčiak, Michal; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli, Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi; Heyl, Jeremy; Iwakiri, Wataru; Kislat, Fabian; Kitaguchi, Takao; Kolodziejczak, Jeffery J.; La Monaca, Fabio; Latronico, Luca; Maldera, Simone; Manfreda, Alberto; Ng, C. -Y.; Omodei, Nicola; Oppedisano, Chiara; Papitto, Alessandro; Pavlov, George G.; Pesce-Rollins, Melissa; Pilia, Maura; Possenti, Andrea; Poutanen, Juri; Rankin, John; Ratheesh, Ajay; Roberts, Oliver J.; Sgrò, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre, Gloria; Swartz, Douglas A.; Tamagawa, Toru; Taverna, Roberto; Tawara, Yuzuru; Thomas, Nicholas E.; Tombesi, Francesco; Trois, Alessio; Tsygankov, Sergey S.; Turolla, Roberto; Vink, Jacco; Weisskopf, Martin C.; Xie, Fei; Zane, SilviaThe magnetic-field conditions in astrophysical relativistic jets can be probed by multiwavelength polarimetry, which has been recently extended to X-rays. For example, one can track how the magnetic field changes in the flow of the radiating particles by observing rotations of the electric vector position angle ¿. Here we report the discovery of a ¿X rotation in the X-ray band in the blazar Markarian¿421 at an average flux state. Across the 5¿days of Imaging X-ray Polarimetry Explorer observations on 4¿6 and 7¿9 June 2022, ¿X rotated in total by ¿360°. Over the two respective date ranges, we find constant, within uncertainties, rotation rates (80¿±¿9° per day and 91¿±¿8° per day) and polarization degrees (¿X¿=¿10%¿±¿1%). Simulations of a random walk of the polarization vector indicate that it is unlikely that such rotation(s) are produced by a stochastic process. The X-ray-emitting site does not completely overlap the radio, infrared and optical emission sites, as no similar rotation of ¿ was observed in quasi-simultaneous data at longer wavelengths. We propose that the observed rotation was caused by a helical magnetic structure in the jet, illuminated in the X-rays by a localized shock propagating along this helix. The optically emitting region probably lies in a sheath surrounding an inner spine where the X-ray radiation is released. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.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). The IAA-CSIC group acknowledges financial support from the grant CEX2021-001131-S funded by MCIN/AEI/10.13039/501100011033 to the Instituto de Astrofisica de Andalucia-CSIC and through grant 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). 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. Mauna Kea, 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. Some of the data reported here are based on observations made with the Nordic Optical Telescope, owned in collaboration with 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. E.L. was supported by Academy of Finland projects 317636 and 320045. 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 NOT. We are grateful to V. Braga, M. Monelli and M. Saenchez Benavente for performing the observations at the Nordic Optical Telescope. Part of the French contributions is supported by the Scientific Research National Center (CNRS) and the French spatial agency (CNES). 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 research was conducted in part using the Mimir instrument, jointly developed at Boston University and Lowell Observatory and supported by NASA, NSF and the W.M. Keck Foundation. We thank D. Clemens for guidance in the analysis of the Mimir data. This work was supported by JST, the establishment of university fellowships towards the creation of science and technology innovation, grant number JPMJFS2129. This work was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant number JP21H01137. This work was also partially supported by the 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 the Kanata Telescope. Some of the data are based on observations collected at the Observatorio de Sierra Nevada, owned and operated by the Instituto de Astrofisica de Andalucia (IAA-CSIC). Further data are based on observations collected at the Centro Astronomico Hispano en Andalucia (CAHA), operated jointly by Junta de Andalucia and Consejo Superior de Investigaciones Cientificas (IAA-CSIC). This research has made use of data from the RoboPol programme, 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. 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 programme under grant agreement no. 771282. C.C. acknowledges support from the European Research Council (ERC) under the HORIZON ERC Grants 2021 programme under grant agreement no. 101040021. The research at Boston University was supported in part by National Science Foundation grant AST-2108622, NASA Fermi Guest Investigator grant 80NSSC21K1917 and 80NSSC22K1571, and NASA Swift Guest Investigator grant 80NSSC22K0537. This work was supported by NSF grant AST-2109127. We acknowledge the use of public data from the Swift data archive. Data from the Steward Observatory spectropolarimetric monitoring project were used. This programme is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, NNX12AO93G and NNX15AU81G. 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 no 306531). This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near-Earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284 and 80NSSC18K1575; by-products of the NEO search include images and catalogues from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory and The Millennium Institute of Astrophysics (MAS), Chile. The Very Long Baseline Array is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under a cooperative agreement by Associated Universities, Inc

Plants used for making recreational tea in Europe: A review based on specific research sites

This paper is a review of local plants used in water infusions as aromatic and refreshing hot beverages (recreational tea) consumed in food-related settings in Europe, and not for specific medicinal purposes. The reviewed 29 areas are located across Europe, covering the post-Soviet countries, eastern and Mediterranean Europe. Altogether, 142 taxa belonging to 99 genera and 40 families were reported. The most important families for making herbal tea in all research areas were Lamiaceae and Asteraceae, while Rosaceae was popular only in eastern and central Europe. With regards to botanical genera, the dominant taxa included Mentha, Tilia, Thymus, Origanum, Rubus and Matricaria. The clear favorite was Origanum vulgare L., mentioned in 61% of the regions. Regionally, other important taxa included Rubus idaeus L. in eastern Europe, Chamaemelum nobile (L.) All. in southern Europe and Rosa canina L. in central Europe. Future research on the pharmacological, nutritional and chemical properties of the plants most frequently used in the tea-making process is essential to ensure their safety and appropriateness for daily consumption. Moreover, regional studies dedicated to the study of local plants used for making recreational tea are important to improve our understanding of their selection criteria, cultural importance and perceived properties in Europe and abroad. © 2013 Sõukand et al.; licensee BioMed Central Ltd

Discovery of X-ray polarization angle rotation in active galaxy Mrk 421

The magnetic field conditions in astrophysical relativistic jets can be probed by multiwavelength polarimetry, which has been recently extended to X-rays. For example, one can track how the magnetic field changes in the flow of the radiating particles by observing rotations of the electric vector position angle $\Psi$. Here we report the discovery of a $\Psi_{\mathrm x}$ rotation in the X-ray band in the blazar Mrk 421 at an average flux state. Across the 5 days of Imaging X-ray Polarimetry Explorer (IXPE) observations of 4-6 and 7-9 June 2022, $\Psi_{\mathrm x}$ rotated in total by $\geq360^\circ$. Over the two respective date ranges, we find constant, within uncertainties, rotation rates ($80 \pm 9$ and $91 \pm 8 ^\circ/\rm day$) and polarization degrees ($\Pi_{\mathrm x}=10\%\pm1\%$). Simulations of a random walk of the polarization vector indicate that it is unlikely that such rotation(s) are produced by a stochastic process. The X-ray emitting site does not completely overlap the radio/infrared/optical emission sites, as no similar rotation of $\Psi$ was observed in quasi-simultaneous data at longer wavelengths. We propose that the observed rotation was caused by a helical magnetic structure in the jet, illuminated in the X-rays by a localized shock propagating along this helix. The optically emitting region likely lies in a sheath surrounding an inner spine where the X-ray radiation is released

Magnetic Field Properties inside the Jet of Mrk 421: Multiwavelength Polarimetry Including the Imaging X-ray Polarimetry Explorer

We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measurements on 2022 December 6-8. We detected X-ray polarization of Mrk 421 with a degree of $\Pi_{\rm X}$=14$\pm$1$\%$ and an electric-vector position angle $\psi_{\rm X}$=107$\pm$3$^{\circ}$ in the 2-8 keV band. From the time variability analysis, we find a significant episodic variation in $\psi_{\rm X}$. During 7 months from the first IXPE pointing of Mrk 421 in 2022 May, $\psi_{\rm X}$ varied across the range of 0$^{\circ}$ to 180$^{\circ}$, while $\Pi_{\rm X}$ maintained similar values within $\sim$10-15$\%$. Furthermore, a swing in $\psi_{\rm X}$ in 2022 June was accompanied by simultaneous spectral variations. The results of the multiwavelength polarimetry show that the X-ray polarization degree was generally $\sim$2-3 times greater than that at longer wavelengths, while the polarization angle fluctuated. Additionally, based on radio, infrared, and optical polarimetry, we find that rotation of $\psi$ occurred in the opposite direction with respect to the rotation of $\psi_{\rm X}$ over longer timescales at similar epochs. The polarization behavior observed across multiple wavelengths is consistent with previous IXPE findings for HSP blazars. This result favors the energy-stratified shock model developed to explain variable emission in relativistic jets. The accompanying spectral variation during the $\psi_{\rm X}$ rotation can be explained by a fluctuation in the physical conditions, e.g., in the energy distribution of relativistic electrons. The opposite rotation direction of $\psi$ between the X-ray and longer-wavelength polarization accentuates the conclusion that the X-ray emitting region is spatially separated from that at longer wavelengths.Comment: 17 pages, 13 figures, 4 tables; Accepted for publication in A&

Purification of lactulose derived-galactooligosaccharides from enzymatic reaction mixtures

This study compares two different procedures for purification of lactulose-derived galactooligosaccharides (GOS) using fresh Saccharomyces cerevisiae yeast or activated charcoal with water or ethanol/water solutions for selective removal of monosaccharides. Yeast fermentation allowed the complete removal of monosaccharides without any losses of di- and oligosaccharides; however besides ethanol, glycerol and higher alcohols difficult to remove are also produced. The presence of higher alcohols affects the sensory quality of the lactulose-derived GOS and may limit its use in certain food applications. Fractionation of these oligosaccharides using activated charcoal was compared with that of lactose-derived GOS the latter being the most strongly adsorbed. When water was utilised as solvent, all monosaccharides were removed, as well as about 20% of unreacted disaccharides. Removal of tri-, tetra- and pentasaccharides was not observed. Using water/ethanol mixtures, desorption of oligosaccharides increased with ethanol content, allowing the selective recovery of different sugar fractions.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness (AGL2017-84614-C2-1-R), the Autonomous Community of Madrid (project ALIBIRD-CM S-2013/ABI-2728) and Spanish Danone Institute. L. C. Julio-González thanks the governorship of Bolivar–Colombia for the scholarship granted in the project “Bolívar gana con Ciencia”. “L.R-A. thanks the Spanish Research Council (CSIC) and the Spanish Ministry of Economy, Industry and Competitiveness for a Juan de la Cierva contract”. WPeer reviewe

New Methodologies for the Extraction and Fractionation of Bioactive Carbohydrates from Mulberry (Morus alba) Leaves

Pressurized liquid extraction (PLE) was applied for the first time to extract bioactive low molecular weight carbohydrates (iminosugars and inositols) from mulberry (Morus alba) leaves. Under optimized conditions, PLE provided a similar yield to the conventional process used to extract these bioactives, but in less time (5 vs 90 min). To remove carbohydrates that interfere with the bioactivity of iminosugars from PLE extracts, two fractionation treatments were evaluated: yeast (Saccharomyces cerevisiae) incubation and cation-exchange chromatography (CEC). Both methods allowed complete removal of major soluble carbohydrates (fructose, glucose, galactose, and sucrose), without affecting the content of mulberry bioactives. As an advantage over CEC, the yeast treatment preserves bioactive inositols, and it is an affordable methodology that employs food grade solvents. This work found PLE followed by yeast treatment to be an easily scalable and automatable procedure that can be implemented in the food industry

The project to understand and research preterm pregnancy outcomes and stillbirths in South Asia (PURPOSe): a protocol of a prospective, cohort study of causes of mortality among preterm births and stillbirths

Abstract Background In South Asia, where most stillbirths and neonatal deaths occur, much remains unknown about the causes of these deaths. About one-third of neonatal deaths are attributed to prematurity, yet the specific conditions which cause these deaths are often unclear as is the etiology of stillbirths. In low-resource settings, most women are not routinely tested for infections and autopsy is rare. Methods This prospective, cohort study will be conducted in hospitals in Davengere, India and Karachi, Pakistan. All women who deliver either a stillbirth or a preterm birth at one of the hospitals will be eligible for enrollment. With consent, the participant and, when applicable, her offspring, will be followed to 28-days post-delivery. A series of research tests will be conducted to determine infection and presence of other conditions which may contribute to the death. In addition, all routine clinical investigations will be documented. For both stillbirths and preterm neonates who die ≤ 28 days, with consent, a standard autopsy as well as minimally invasive tissue sampling will be conducted. Finally, an expert panel will review all available data for stillbirths and neonatal deaths to determine the primary and contributing causes of death using pre-specified guidance. Conclusion This will be among the first studies to prospectively obtain detailed information on causes of stillbirth and preterm neonatal death in low-resource settings in Asia. Determining the primary causes of death will be important to inform strategies most likely to reduce the high mortality rates in South Asia. Trial registration Clinicaltrials.gov (NCT03438110) Clinical Trial Registry of India (CTRI/2018/03/012281)