17 research outputs found

    IAA : Información y actualidad astronómica (46)

    Get PDF
    Sumario: UPWARDS: ciencia nueva para un planeta viejo.-- La teoría del estado estacionario.-- Sorpresas en la nebulosa del Huevo Podrido.-- DECONSTRUCCIÓN Y otros ENSAYOS. Binarias de rayos X.-- Homenaje a Javier Gorosabel.-- EL “MOBY DICK” DE... Christina Thöne (IAA).-- CIENCIA EN HISTORIAS...Maria Mitchell.-- ACTUALIDAD.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Mercurio.N

    The advanced image slicers of OCTOCAM

    Get PDF
    OCTOCAM is the new large Gemini instrument in building. It is an imaging spectrograph with 8 cameras covering the range 370 nm to 2350 nm at a typical resolution of 3000-4000. It will have 2 IFUs, one for normal operation over all wavelengths, the other for AO in the NIR only and with a smaller field but a higher spectral resolution. Currently, no IFU exists that covers the entire range of VIS and NIR in a single observation. Such an IFU would have a number of applications: It can be used for resolved studies of HII regions over a broad wavelength range and emission line galaxies over a broad redshift range using the same set of emission lines. Another application is to observe transients with only arcseconds localization very early without waiting for a sub-arcsecond position, hence allowing to obtain very valuable early data. For bright transients such as SNe and GRBs we can study the immediate environment in detail, and even use the actual transient as AO tip-tilt star to study the environment at high spectral and very high angular resolutions. The IFUs will be Advanced Image Slicers, a proven concept now in use in many instruments around the world including Gemini NIFS, VLT MUSE and KMOS, and JWST NIRSpec. The normal operation slicer will have a field of 9.7> x 6.8> with 17 slices 0.4> wide giving 0.18> x 0.4> spaxels. The slices are smaller than the standard slit size of 0.54> (3 pixels) so will deliver higher spectral resolution. This IFU will deliver much higher performances than the GMOS IFU and NIFS with a larger field of view and spectral range but also considerably fewer pixels per arsec2 then reducing the readout noise. With its wavelength range starting at 370 nm, diamond machining cannot be used. A glass slicer system will have to be used as in MUSE. The wavelength range will however be much larger covering the whole VIS and NIR range. Modern reflection coatings as UV enhanced silver can be used but a trade-off may be better by starting at a longer wavelength to get higher transmission. Special consideration is necessary for the fore-optics which cannot be diamond machined and for the overall design due to the limited space envelope. The AO slicer will have a field of 2.5> x 3.6> with 31 slices 0.08> wide imaged on 2 pixels in the spectral direction to get proper sampling. The fore-optics will magnify the beam in both directions but with different magnifications to get spaxels of 0.08> x 0.08>. The smaller slice image width will give a spectral resolution of about 5000 including aberrations, about the same than NIFS but covering all 4 NIR bands at once. This slicer uses a slit 60% longer than OCTOCAM is designed for. It is possible because the magnification reduces the beam size so the aberrations and vignetting. ©2018 SPIE

    Dwarf galaxies as hosts of stellar explosions: gas kinematics and abundances in 3D

    No full text
    In: Dwarf galaxies: from the deep universe to the present; edited by:McQuinn, KBW; Stierwalt, S.; ISBN:978-1-108-47161-9.--Conference: 344th Symposium of the International-Astronomical-Union (IAU), Vienna, Austria, Aug 20-24, 2018.The hosts of long Gamma-ray bursts (GRBs) are places of intense star-formation, which, at low redshift, are primarily low-mass dwarf starburst galaxies. Spatially resolved studies of these galaxies are still sparse, even more so at high spectral resolution where we can probe gas kinematics, in- and outflows and differences in abundance between different components. Here we present the first high resolution IFU sample of six low redshift GRB hosts, all dwarf starbursts. All galaxies in our sample show evidence for excess emission or broad emission components, with velocities of 100-200 kms(-1). For GRB 030329, outflowing gas had also been observed in absorption in spectra of the GRB afterglow. The high velocity emission is usually blue shifted, connected to the brightest star-forming regions and more metal rich than the narrow component associated with the emission of the general host ISM. This gives strong indications that the excess emission/broad component is indeed associated to a starburst wind as observed in many field star-burst galaxies and a sign for the intense ongoing star-formation in those galaxies

    Exploring 3D data of Dwarf Galaxies

    No full text
    In: Dwarf galaxies: from the deep universe to the present; edited by:McQuinn, KBW; Stierwalt, S.; ISBN:978-1-108-47161-9.--Conference: 344th Symposium of the International-Astronomical-Union (IAU), Vienna, Austria, Aug 20-24, 2018.Dwarf irregular galaxies are places of ongoing star-formation in the low-redshift Universe. Low metallicity dwarfs were originally thought to be the youngest galaxies in the local Universe, however, there is now evidence that they consist of matter which has previously undergone evolution and is enriched by star-formation. Here we present a sample of seven nearby metal-poor dwarf galaxies with a young stellar populations selected from the SDSS which we study using integral field unit (IFU) data from the VIMOS instrument, covering the spectral range between the He II 4686 line and the [SII] 6718/6733 angstrom doublet. We present property maps across the galaxies and compare different galaxies and different HII regions within the same galaxy. We find that the properties within one galaxy are not uniform and they also differ between different galaxies concerning star-formation, kinematics and metallicity and morphology. The observed differences across individual galaxies together with disturbed kinematics and morphologies can be interpreted as possible signs of recent interactions and/or mergers. Additionally, we present a comparison of different metallicity calibrations and search for systematic differences obtained using different methods

    GRANDMA observations of advanced LIGO's and advanced Virgo's third observational campaign

    No full text
    Full list of authors: Antier, S.; Agayeva, S.; Almualla, M.; Awiphan, S.; Baransky, A.; Barynova, K.; Beradze, S.; Blažek, M.; Boër, M.; Burkhonov, O.; Christensen, N.; Coleiro, A.; Corre, D.; Coughlin, M. W.; Crisp, H.; Dietrich, T.; Ducoin, J. -G.; Duverne, P. -A.; Marchal-Duval, G.; Gendre, B.; Gokuldass, P.; Eggenstein, H. B.; Eymar, L.; Hello, P.; Howell, E. J.; Ismailov, N.; Kann, D. A.; Karpov, S.; Klotz, A.; Kochiashvili, N.; Lachaud, C.; Leroy, N.; Lin, W. L.; Li, W. X.; Mašek, M.; Mo, J.; Menard, R.; Morris, D.; Noysena, K.; Orange, N. B.; Prouza, M.; Rattanamala, R.; Sadibekova, T.; Saint-Gelais, D.; Serrau, M.; Simon, A.; Stachie, C.; Thöne, C. C.; Tillayev, Y.; Turpin, D.; de Ugarte Postigo, A.; Vasylenko, V.; Vidadi, Z.; Was, M.; Wang, X. F.; Zhang, J. J.; Zhang, T. M.; Zhang, X. H.GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of 25 telescopes of different sizes, including both photometric and spectroscopic facilities. The network aims to coordinate follow-up observations of gravitational-wave (GW) candidate alerts, especially those with large localization uncertainties, to reduce the delay between the initial detection and the optical confirmation. In this paper, we detail GRANDMA's observational performance during Advanced LIGO/Advanced Virgo Observing Run 3 (O3), focusing on the second part of O3; this includes summary statistics pertaining to coverage and possible astrophysical origin of the candidates. To do so, we quantify our observation efficiency in terms of delay between GW candidate trigger time, observations, and the total coverage. Using an optimized and robust coordination system, GRANDMA followed-up about 90 per cent of the GW candidate alerts, that is 49 out of 56 candidates. This led to coverage of over 9000 deg2 during O3. The delay between the GW candidate trigger and the first observation was below 1.5 h for 50 per cent of the alerts. We did not detect any electromagnetic counterparts to the GW candidates during O3, likely due to the very large localization areas (on average thousands of degrees squares) and relatively large distance of the candidates (above 200 Mpc for 60 per cent of binary neutron star, BNS candidates). We derive constraints on potential kilonova properties for two potential BNS coalescences (GW190425 and S200213t), assuming that the events' locations were imaged. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.Parts of this research were conducted by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), through project number CE170100004. EJH acknowledges support from an Australian Research Council DECRA Fellowship (DE170100891). AdUP and CCT acknowledge support from Ramon y Cajal fellowships RyC-2012-09975 and RyC-2012-09984 and the Spanish Ministry of Economy and Competitiveness through project AYA2017-89384-P. DAK acknowledges Spanish research project RTI2018-098104-J-I00 (GRBPhot). MB acknowledges funding as 'personal tecnico de apoyo' under fellowship number PTA2016-13192-I. SA is supported by the CNES Postdoctoral Fellowship at Laboratoire AstroParticule et Cosmologie. SA and CL acknowledge the financial support of the Programme National Hautes Energies (PNHE). DT acknowledges the financial support of CNES postdoctoral program. UBAI acknowledges support from the Ministry of Innovative Development through projects FA-Atech-2018-392 and VA-FA-F-2-010. SB acknowledges Shota Rustaveli National Science Foundation (SRNSF) grant no. -PHDF/18-1327. TAROT has been built with the support of the Institut National des Sciences de l'Univers, CNRS, France. TAROT is funded by the CNES and thanks the help of the technical staff of the Observatoire de Haute Provence, OSUPytheas. MP, SK, and MM are supported by European Structural and Investment Fund and the Czech Ministry of Education, Youth and Sports (Projects CZ.02.1.01/0.0/0.0/16 013/0001402, CZ.02.1.01/0.0/0.0/16 013/0001403, and CZ.02.1.01/0.0/0.0/15 003/0000437). NBO, DM, and PG acknowledge financial support from NASA-MUREP-MIRO grant NNX15AP95A, NASA-EPSCoR grant NNX13AD28A, and NSF EiR AST Award 1901296. The GRANDMA collaboration thank the amateur participants to the kilonova-catcher program. The kilonova-catcher program is supported by the IdEx Universite de Paris, ANR-18-IDEX-0001. This research made use of the crossmatch service provided by CDS, Strasbourg. We thank Ulrich Hopp to provide the precise date of observations for AT2019wxt Wendelstein optical observations.Peer reviewe

    GRB 160410A: The first chemical study of the interstellar medium of a short GRB

    No full text
    Full list of authors: Agüı́ Fernández, J. F.; Thone, C. C.; Kann, D. A.; Postigo, A. de Ugarte; Selsing, J.; Schady, P.; Yates, R. M.; Greiner, J.; Oates, S. R.; Malesani, D. B.; Xu, D.; Klotz, A.; Campana, S.; Rossi, A.; Perley, D. A.; Blazek, M.; D'Avanzo, P.; Giunta, A.; Hartmann, D.; Heintz, K. E.; Jakobsson, P.; Kirkpatrick, C. C., IV; Kouveliotou, C.; Melandri, A.; Pugliese, G.; Salvaterra, R.; Starling, R. L. C.; Tanvir, N. R.; Vergani, S. D.; Wiersema, K.Short gamma-ray bursts (SGRBs) are produced by the coalescence of compact binary systems which are remnants of massive stars. GRB 160410A is classified as a short-duration GRB with extended emission and is currently the farthest SGRB with a redshift determined from an afterglow spectrum and also one of the brightest SGRBs to date. The fast reaction to the Neil Gehrels Swift Observatory alert allowed us to obtain a spectrum of the afterglow using the X-shooter spectrograph at the Very Large Telescope (VLT). The spectrum shows several absorption features at a redshift of z = 1.7177, in addition, we detect two intervening systems at z = 1.581 and z = 1.444. The spectrum shows Ly α in absorption with a column density of log (N(H I)/cm2) = 21.2 ± 0.2 which, together with Fe II, C II, Si II, Al II, and O I, allow us to perform the first study of chemical abundances in a SGRB host galaxy. We determine a metallicity of [X/H] = −2.3 ± 0.2 for Fe II and −2.5 ± 0.2 for Si II and no dust depletion. We also find no evidence for extinction in the afterglow spectral energy distribution modelling. The environment has a low degree of ionization and the C IV and Si IV lines are completely absent. We do not detect an underlying host galaxy down to deep limits. Additionally, we compare GRB 160410A to GRB 201221D, another high-z short GRB that shows absorption lines at z = 1.045 and an underlying massive host galaxy. © 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.JFAF acknowledges support from the Spanish Ministerio de Ciencia, Innovación y Universidades through the grant PRE2018-086507. DAK and JFAF acknowledge support from Spanish National Research Project RTI2018-098104-J-I00 (GRBPhot). AdUP acknowledges funding from a Ramón y Cajal fellowship (RyC-2012-09975). MB acknowledges funding associated to a personal tecnico de apoyo fellowship (PTA2016-13192-I). DBM acknowledges research grant 19054 from VILLUM FONDEN. Part of the funding for Gamma-Ray burst Optical and Near-infrared Detector (GROND) (both hardware as well as personnel) was generously granted from the Leibniz Prize to Prof. G. Hasinger (DFG grant HA 1850/28-1). AR acknowledges support from the Istituto Nazionale di Astrofisica (INAF) project Premiale Supporto Arizona & Italia.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).Peer reviewe

    GRBSpec and GRBPhot: Social networks to share gamma ray burst data

    No full text
    Software and Cyberinfrastructure for Astronomy VI 2020; Virtual, Online; United States; 14 December 2020 through 18 December 2020; Code 166383.--Proceedings of SPIE - The International Society for Optical Engineering Volume 11452, 2020, Article number 1145218 (8 pp)GRBSpec and GRBPhot are two databases designed for the storage and analysis of gamma-ray burst (GRB) data. GRBSpec is devoted to spectroscopic observations, GRBPhot to photometric data. Both databases have a detailed search engine and offer online graphical tools for plotting and data analysis. They aim to publicly share these specialised data among the astronomical community and provide quick online measurements and plots. The databases can be accessed through http://grbpsec.iaa.es and http://grbphot.iaa.es, respectively. As of November 2020, the database already contained 2013 files belonging to 810 spectra of 268 different GRBs. © 2020 SPIE.GRBSpec and GRBPhot have been made possible through the generous contribution of a 2016 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation. AdUP and CT acknowledge support from Ram´on y Cajal fellowships (RyC-2012-09975, RyC-2012-09984). MB acknowledges funding associated to a personal t´ecnico de apoyo fellowship (PTA2016-13192-I). DAK acknowledges support from Spanish National Research Project RTI2018-098104-J-I00 (GRBPhot). LI was supported by grants from VILLUM FONDEN (project number 16599 and 25501). JFAF acknowledge financial support from Ministerio de Ciencia, Innovaci´on y Universidades fellowship (PRE2018-086507)

    Beryllium detection in the very fast nova ASASSN-16kt (V407 Lupi)

    No full text
    We present high-resolution spectroscopic observations of the fast nova ASASSN-16kt (V407 Lup). A close inspection of spectra obtained at early stages has revealed the presence of low-ionization lines, and among the others we have identified the presence of the ionized Be doublet in a region relatively free from possible contaminants. After studying their intensities, we have inferred that ASASSN-16kt has produced (5.9-7.7)× 10M of Be. The identification of bright Ne lines may suggest that the nova progenitor is a massive (1.2 M) oxygen-neon white dwarf. The high outburst frequency of oxygen-neon novae implies that they likely produce an amount of Be similar, if not larger, to that produced by carbon-oxygen novae, then confirming that classical novae are among the main factories of lithium in the Galaxy.© 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.LI, CT, ZC and AdUP acknowledge support from the Spanish research project AYA 2014-58381-P. CT and AdUP furthermore acknowledge support from Ramn y Cajal fellowships Ramon y Cajal (RyC)-2012-09984 and RyC-2012-09975. ZC also acknowledges support from the Juan de la Cierva Incorporacion fellowship IJCI-2014-21669. LV acknowledge support from Commission Nacional de Investigacion Cientifica y Tecnologica (CONICYT) through project Fondecyt n. 1171364. AZ acknowledge support from Conicyt through the 'Beca Doctorado Nacional' 21170536. Support for JLP is provided in part by Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT) through the grant 1151445 and by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS.Peer Reviewe

    The host of the Type I SLSN 2017egm: A young, sub-solar metallicity environment in a massive spiral galaxy

    No full text
    Context. Type I superluminous supernova (SLSN) host galaxies are predominantly low-metallicity, highly star-forming (SF) dwarfs. One of the current key questions is whether Type I SLSNe can only occur in such environments and hosts. Aims. Here we present an integral-field study of the massive, high-metallicity spiral NGC 3191, the host of SN 2017egm, the closest Type I SLSN known to date. We use data from PMAS/CAHA and the public MaNGA survey to shed light on the properties of the SLSN site and the origin of star formation in this non-starburst spiral galaxy. Methods. We map the physical properties of different H ii regions throughout the galaxy and characterise their stellar populations using the STARLIGHT fitting code. Kinematical information allows us to study a possible interaction with its neighbouring galaxy as the origin of recent star formation activity which could have caused the SLSN. Results. NGC 3191 shows intense star formation in the western part with three large SF regions of low metallicity. Taking only the properties of emitting gas, the central regions of the host have a higher metallicity, a lower specific star formation rate, and lower ionisation. Modelling the stellar populations gives a different picture: the SLSN region has two dominant stellar populations with different ages, the younger one with an age of 2-10 Myr and lower metallicity, likely the population from which the SN progenitor originated. Emission line kinematics of NGC 3191 show indications of interaction with its neighbour MCG+08-19-017 at ∼45 kpc, which might be responsible for the recent starburst. In fact, this galaxy pair has hosted a total of four SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl (Type II), and 2017egm, underlying the enhanced SF in both galaxies due to interaction. Conclusions. Our study shows that care should be taken when interpreting global host and even gas properties without looking at the stellar population history of the region. The SLSNe seem to be consistent with massive stars (>20 M) requiring low metallicity (<0.6 Z), environments that can also occur in massive late-type galaxies, but not necessarily with starbursts.© ESO, 2018.We thank the referee for the constructive comments that have improved the paper. We also thank Steve Schulze and Yan Lin for their important comments to the paper. L.I., C.T., Z.C., A.d.U.P., and D.A.K. acknowledge support from the Spanish research project AYA2014-58381-P. C.T. and A.d.U.P. also acknowledge support from Ramon y Cajal fellowships RyC-2012-09984 and RyC-2012-09975. D.A.K. and Z.C. acknowledge support from Juan de la Cierva Incorporacion fellowships IJCI-2015-26153 and IJCI-2014-21669. R.G.B. acknowledges support from the Spanish Ministerio de Economia y Competitividad, through projects AYA2016-77846-P and AYA2014-57490-P. L.I. wishes to thank Anna Serena Esposito for her kind availability and support in organising the figures presented in this paper.Peer reviewe
    corecore