TY  - JOUR
A1  - Abdalla, Hassan E.
A1  - Abramowski, Attila
A1  - Aharonian, Felix A.
A1  - Benkhali, Faiçal Ait
A1  - Akhperjanian, A. G.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Arrieta, M.
A1  - Aubert, Pierre
A1  - Backes, Michael
A1  - Balzer, Arnim
A1  - Barnard, Michelle
A1  - Becherini, Yvonne
A1  - Tjus, Julia Becker
A1  - Berge, David
A1  - Bernhard, Sabrina
A1  - Bernlöhr, K.
A1  - Birsin, E.
A1  - Blackwell, R.
A1  - Bottcher, Markus
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Bregeon, Johan
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bryan, Mark
A1  - Bulik, Tomasz
A1  - Capasso, M.
A1  - Carr, John
A1  - Casanova, Sabrina
A1  - Chakraborty, N.
A1  - Chalme-Calvet, R.
A1  - Chaves, Ryan C. G.
A1  - Chen, Andrew
A1  - Chevalier, J.
A1  - Chretien, M.
A1  - Colafrancesco, Sergio
A1  - Cologna, Gabriele
A1  - Condon, B.
A1  - Conrad, Jan
A1  - Couturier, C.
A1  - Cui, Y.
A1  - Davids, I. D.
A1  - Degrange, B.
A1  - Deil, Christoph
A1  - deWilt, P.
A1  - Djannati-Atai, Arache
A1  - Domainko, Wilfried
A1  - Donath, Axel
A1  - Dubus, Guillaume
A1  - Dutson, Kate
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Edwards, T.
A1  - Egberts, Kathrin
A1  - Eger, P.
A1  - Ernenwein, J. -P.
A1  - Eschbach, S.
A1  - Farnier, C.
A1  - Fegan, Stuart
A1  - Fernandes, M. V.
A1  - Fiasson, A.
A1  - Fontaine, G.
A1  - Foerster, A.
A1  - Funk, S.
A1  - Füßling, Matthias
A1  - Gabici, Stefano
A1  - Gajdus, M.
A1  - Gallant, Y. A.
A1  - Garrigoux, T.
A1  - Giavitto, Gianluca
A1  - Giebels, B.
A1  - Glicenstein, J. F.
A1  - Gottschall, Daniel
A1  - Goyal, A.
A1  - Grondin, M. -H.
A1  - Grudzinska, M.
A1  - Hadasch, Daniela
A1  - Hahn, J.
A1  - Hawkes, J.
A1  - Heinzelmann, G.
A1  - Henri, Gilles
A1  - Hermann, G.
A1  - Hervet, Olivier
A1  - Hillert, A.
A1  - Hinton, James Anthony
A1  - Hofmann, Werner
A1  - Hoischen, Clemens
A1  - Holler, M.
A1  - Horns, D.
A1  - Ivascenko, Alex
A1  - Jacholkowska, A.
A1  - Jamrozy, Marek
A1  - Janiak, M.
A1  - Jankowsky, D.
A1  - Jankowsky, Felix
A1  - Jingo, M.
A1  - Jogler, Tobias
A1  - Jouvin, Lea
A1  - Jung-Richardt, Ira
A1  - Kastendieck, M. A.
A1  - Katarzynski, Krzysztof
A1  - Katz, Uli
A1  - Kerszberg, D.
A1  - Khelifi, B.
A1  - Kieffer, M.
A1  - King, J.
A1  - Klepser, S.
A1  - Klochkov, Dmitry
A1  - Kluzniak, W.
A1  - Kolitzus, D.
A1  - Komin, Nu.
A1  - Kosack, K.
A1  - Krakau, S.
A1  - Kraus, Michael
A1  - Krayzel, F.
A1  - Kruger, P. P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lau, Jeanie
A1  - Lees, J. -P.
A1  - Lefaucheur, J.
A1  - Lefranc, V.
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Leser, Eva
A1  - Lohse, Thomas
A1  - Lorentz, M.
A1  - Lui, R.
A1  - Lypova, Iryna
A1  - Marandon, Vincent
A1  - Marcowith, Alexandre
A1  - Mariaud, C.
A1  - Marx, R.
A1  - Maurin, G.
A1  - Maxted, N.
A1  - Mayer, Michael
A1  - Meintjes, Petrus Johannes
A1  - Menzler, U.
A1  - Meyer, Manuel
A1  - Mitchell, A. M. W.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mora, K.
A1  - Moulin, Emmanuel
A1  - Murach, T.
A1  - de Naurois, Mathieu
A1  - Niederwanger, F.
A1  - Niemiec, J.
A1  - Oakes, L.
A1  - Odaka, Hirokazu
A1  - Ohm, Stefan
A1  - Oettl, S.
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Padovani, Marco
A1  - Panter, M.
A1  - Parsons, R. D.
A1  - Arribas, M. Paz
A1  - Pekeur, N. W.
A1  - Pelletier, G.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pita, S.
A1  - Poon, Helen
A1  - Prokhorov, Dmitry
A1  - Prokoph, Heike
A1  - Puehlhofer, Gerd
A1  - Punch, Michael
A1  - Quirrenbach, Andreas
A1  - Raab, S.
A1  - Reimer, Anita
A1  - Reimer, Olaf
A1  - Renaud, M.
A1  - de los Reyes, R.
A1  - Rieger, Frank
A1  - Romoli, Carlo
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Sahakian, V.
A1  - Salek, David
A1  - Sanchez, David A.
A1  - Santangelo, Andrea
A1  - Sasaki, Manami
A1  - Schlickeiser, Reinhard
A1  - Schussler, F.
A1  - Schulz, Andreas
A1  - Schwanke, U.
A1  - Schwemmer, S.
A1  - Seyffert, A. S.
A1  - Shafi, N.
A1  - Simoni, R.
A1  - Sol, H.
A1  - Spanier, Felix
A1  - Spengler, G.
A1  - Spiess, F.
A1  - Stawarz, Lukasz
A1  - Steenkamp, R.
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tluczykont, Martin
A1  - Trichard, C.
A1  - Tuffs, R.
A1  - van der Walt, Johan
A1  - van Eldik, Christopher
A1  - van Soelen, Brian
A1  - Vasileiadis, Georges
A1  - Veh, J.
A1  - Venter, C.
A1  - Viana, A.
A1  - Vincent, P.
A1  - Vink, Jacco
A1  - Voisin, F.
A1  - Voelk, Heinrich J.
A1  - Vuillaume, Thomas
A1  - Wadiasingh, Z.
A1  - Wagner, Stefan J.
A1  - Wagner, P.
A1  - Wagner, R. M.
A1  - White, R.
A1  - Wierzcholska, Alicja
A1  - Willmann, P.
A1  - Woernlein, A.
A1  - Wouters, Denis
A1  - Yang, R.
A1  - Zabalza, Victor
A1  - Zaborov, D.
A1  - Zacharias, M.
A1  - Zdziarski, A. A.
A1  - Zech, Andreas
A1  - Zefi, F.
A1  - Ziegler, A.
A1  - Zywucka, Natalia
T1  - Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with HESS
JF  - Physical review letters
N2  - The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using gamma-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant gamma-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section <sigma nu >. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach <sigma nu > values of 6 x 10(-26) cm(3) s(-1) in the W+W- channel for a DM particle mass of 1.5 TeV, and 2 x 10(-26) cm(3) s(-1) in the tau(+)tau(-) channel for a 1 TeV mass. For the first time, ground-based gamma-ray observations have reached sufficient sensitivity to probe <sigma nu > values expected from the thermal relic density for TeV DM particles.
Y1  - 2016
U6  - https://doi.org/10.1103/PhysRevLett.117.111301
SN  - 0031-9007
SN  - 1079-7114
VL  - 117
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - GEN
A1  - Abramowski, Attila
A1  - Aharonian, Felix A.
A1  - Benkhali, Faical Ait
A1  - Akhperjanian, A. G.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Backes, Michael
A1  - Balenderan, Shangkari
A1  - Balzer, Arnim
A1  - Barnacka, Anna
A1  - Becherini, Yvonne
A1  - Tjus, Julia Becker
A1  - Berge, David
A1  - Bernhard, Sabrina
A1  - Bernlöhr, Konrad
A1  - Birsin, E.
A1  - Biteau, Jonathan
A1  - Böttcher, Markus
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Bregeon, Johan
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bryan, Mark
A1  - Bulik, Tomasz
A1  - Carrigan, Svenja
A1  - Casanova, Sabrina
A1  - Chadwick, Paula M.
A1  - Chakraborty, Nachiketa
A1  - Chalme-Calvet, R.
A1  - Chaves, Ryan C. G.
A1  - Chretien, M.
A1  - Colafrancesco, Sergio
A1  - Cologna, Gabriele
A1  - Conrad, Jan
A1  - Couturier, Claire
A1  - Cui, Yudong
A1  - Davids, Isak Delberth
A1  - Degrange, Bernhard
A1  - Deil, Christoph
A1  - deWilt, P.
A1  - Djannati-Ataï, A.
A1  - Domainko, Wilfried
A1  - Donath, Axel
A1  - Dubus, G.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Edwards, Tanya
A1  - Egberts, Kathrin
A1  - Eger, Peter
A1  - Espigat, P.
A1  - Farnier, C.
A1  - Fegan, Stephen
A1  - Feinstein, Fabrice
A1  - Fernandes, Milton Virgilio
A1  - Fernandez, Diane
A1  - Fiasson, A.
A1  - Fontaine, Gerard
A1  - Förster, Andreas
A1  - Fuessling, M.
A1  - Gabici, S.
A1  - Gajdus, M.
A1  - Gallant, Yves A.
A1  - Garrigoux, Tania
A1  - Giavitto, G.
A1  - Giebels, Berrie
A1  - Glicenstein, Jean-Francois
A1  - Gottschall, Daniel
A1  - Grondin, M. -H.
A1  - Grudzinska, M.
A1  - Hadasch, Daniela
A1  - Haeffner, S.
A1  - Hahn, Joachim
A1  - Harris, Jonathan
A1  - Heinzelmann, Götz
A1  - Henri, G.
A1  - Hermann, German
A1  - Hervet, O.
A1  - Hillert, Andreas
A1  - Hinton, James Anthony
A1  - Hofmann, Werner
A1  - Hofverberg, Petter
A1  - Holler, Markus
A1  - Horns, Dieter
A1  - Ivascenko, Alex
A1  - Jacholkowska, A.
A1  - Jahn, C.
A1  - Jamrozy, Marek
A1  - Janiak, M.
A1  - Jankowsky, F.
A1  - Jung-Richardt, I.
A1  - Kastendieck, Max Anton
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Khelifi, B.
A1  - Kieffer, Michel
A1  - Klepser, S.
A1  - Klochkov, Dmitry
A1  - Kluzniak, W.
A1  - Kolitzus, David
A1  - Komin, Nu
A1  - Kosack, Karl
A1  - Krakau, Steffen
A1  - Krayzel, F.
A1  - Krueger, Pat P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lefaucheur, J.
A1  - Lefranc, Valentin
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Lohse, Thomas
A1  - Lopatin, A.
A1  - Lu, Chia-Chun
A1  - Marandon, Vincent
A1  - Marcowith, Alexandre
A1  - Marx, Ramin
A1  - Maurin, G.
A1  - Maxted, Nigel
A1  - Mayer, Michael
A1  - McComb, T. J. Lowry
A1  - Mehault, J.
A1  - Meintjes, P. J.
A1  - Menzler, Ulf
A1  - Meyer, M.
A1  - Mitchell, Alison M. W.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mora, K.
A1  - Moulin, Emmanuel
A1  - Murach, Thomas
A1  - de Naurois, Mathieu
A1  - Niemiec, J.
A1  - Nolan, Sam J.
A1  - Oakes, Louise
A1  - Odaka, Hirokazu
A1  - Ohm, S.
A1  - Optiz, Björn
A1  - Ostrowski, Michal
A1  - Oya, I.
A1  - Panter, Michael
A1  - Parsons, R. Daniel
A1  - Arribas, M. Paz
A1  - Pekeur, Nikki W.
A1  - Pelletier, G.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pita, S.
A1  - Poon, Helen
A1  - Pühlhofer, Gerd
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Reichardt, I.
A1  - Reimer, Anita
A1  - Reimer, Olaf
A1  - Renaud, Metz
A1  - de los Reyes, Raquel
A1  - Rieger, Frank
A1  - Romoli, C.
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Sahakian, Vardan
A1  - Salek, D.
A1  - Sanchez, David M.
A1  - Santangelo, Andrea
A1  - Schlickeiser, Reinhard
A1  - Schuessler, F.
A1  - Schulz, A.
A1  - Schwanke, Ullrich
A1  - Schwarzburg, S.
A1  - Schwemmer, S.
A1  - Sol, H.
A1  - Spanier, Felix
A1  - Spengler, G.
A1  - Spies, Franziska
A1  - Stawarz, Lukasz
A1  - Steenkamp, Riaan
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tluczykont, Martin
A1  - Trichard, C.
A1  - Valerius, K.
A1  - van Eldik, C.
A1  - van Soelen, B.
A1  - Vasileiadis, Georges
A1  - Veh, J.
A1  - Venter, Christo
A1  - Viana, Aion
A1  - Vincent, P.
A1  - Vink, Jacco
A1  - Völk, Heinrich J.
A1  - Volpe, Francesca
A1  - Vorster, Martine
A1  - Vuillaume, T.
A1  - Wagner, S. J.
A1  - Wagner, P.
A1  - Wagner, R. M.
A1  - Ward, Martin
A1  - Weidinger, Matthias
A1  - Weitzel, Quirin
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Willmann, P.
A1  - Woernlein, A.
A1  - Wouters, D.
A1  - Yang, Ruizhi
A1  - Zabalza, Victor
A1  - Zaborov, Dmitry
A1  - Zacharias, M.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zechlin, Hannes -S.
T1  - H.E.S.S. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud (vol 574, A100, 2015)
T2  - Astronomy and astrophysics : an international weekly journal
KW  - gamma rays: general
KW  - ISM: supernova remnants
KW  - ISM: clouds
KW  - errata, addenda
Y1  - 2015
U6  - https://doi.org/10.1051/0004-6361/201425070e
SN  - 1432-0746
VL  - 580
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Acharya, B. S.
A1  - Aramo, C.
A1  - Babic, A.
A1  - Barrio, J. A.
A1  - Baushev, Anton N.
A1  - Tjus, J. Becker
A1  - Berge, David
A1  - Bohacova, M.
A1  - Bonardi, A.
A1  - Brown, A.
A1  - Bugaev, V.
A1  - Bulik, Tomasz
A1  - Burton, M.
A1  - Busetto, G.
A1  - Caraveo, P. A.
A1  - Carosi, R.
A1  - Carr, John
A1  - Chadwick, Paula M.
A1  - Chudoba, J.
A1  - Conforti, V.
A1  - Connaughton, V.
A1  - Contreras, J. L.
A1  - Cotter, G.
A1  - Dazzi, F.
A1  - De Franco, A.
A1  - de la Calle, I.
A1  - Lopez, R. de los Reyes
A1  - De Lotto, B.
A1  - De Palma, F.
A1  - Di Girolamo, T.
A1  - Di Giulio, C.
A1  - Di Pierro, F.
A1  - Dournaux, J. -L.
A1  - Dwarkadas, Vikram V.
A1  - Ebr, J.
A1  - Egberts, Kathrin
A1  - Fesquet, M.
A1  - Fleischhack, H.
A1  - Font, L.
A1  - Fontaine, G.
A1  - Foerster, A.
A1  - Füßling, Matthias
A1  - Garcia, B.
A1  - Lopez, R. Garcia
A1  - Garczarczyk, M.
A1  - Gargano, F.
A1  - Garrido, D.
A1  - Gaug, M.
A1  - Giglietto, N.
A1  - Giordano, F.
A1  - Giuliani, A.
A1  - Godinovic, N.
A1  - Gonzalez, M. M.
A1  - Grabarczyk, T.
A1  - Hassan, T.
A1  - Hoerandel, J.
A1  - Hrabovsky, M.
A1  - Hrupec, D.
A1  - Humensky, T. B.
A1  - Huovelin, J.
A1  - Jamrozy, M.
A1  - Janecek, P.
A1  - Kaaret, P. E.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Khelifi, B.
A1  - Kluzniak, W.
A1  - Kocot, J.
A1  - Komin, N.
A1  - Kubo, H.
A1  - Kushida, J.
A1  - Lamanna, G.
A1  - Lee, W. H.
A1  - Lenain, J. -P.
A1  - Lohse, T.
A1  - Lombardi, S.
A1  - Lopez-Coto, R.
A1  - Lopez-Oramas, A.
A1  - Lucarelli, F.
A1  - Maccarone, M. C.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - Malaguti, G.
A1  - Mandat, D.
A1  - Mazziotta, Mario Nicola
A1  - Meagher, K.
A1  - Mirabal, N.
A1  - Morselli, A.
A1  - Moulin, Emmanuel
A1  - Niemiec, J.
A1  - Nievas, M.
A1  - Nishijima, K.
A1  - Nosek, D.
A1  - Nunio, F.
A1  - Ohishi, M.
A1  - Ohm, S.
A1  - Ong, R. A.
A1  - Orito, R.
A1  - Otte, N.
A1  - Palatka, M.
A1  - Pareschi, G.
A1  - Pech, M.
A1  - Persic, M.
A1  - Pohl, Manuela
A1  - Prouza, M.
A1  - Quirrenbach, A.
A1  - Raino, S.
A1  - Fernandez, G. Rodriguez
A1  - Romano, Patrizia
A1  - Rovero, A. C.
A1  - Rudak, B.
A1  - Schovanek, P.
A1  - Shayduk, M.
A1  - Siejkowski, H.
A1  - Sillanpaa, A.
A1  - Stefanik, S.
A1  - Stolarczyk, T.
A1  - Szanecki, M.
A1  - Szepieniec, T.
A1  - Tejedor, L. A.
A1  - Telezhinsky, Igor O.
A1  - Teshima, M.
A1  - Tibaldo, L.
A1  - Tibolla, O.
A1  - Tovmassian, G.
A1  - Travnicek, P.
A1  - Trzeciak, M.
A1  - Vallania, P.
A1  - van Eldik, C.
A1  - Vercellone, S.
A1  - Vigorito, C.
A1  - Wagner, S. J.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Wierzcholska, A.
A1  - Wilhelm, Alina
A1  - Wojcik, P.
A1  - Yoshikoshi, T.
T1  - The Cherenkov Telescope Array potential for the study of young supernova remnants
JF  - Astroparticle physics
N2  - Supernova remnants (SNRs) are among the most important targets for gamma-ray observatories. Being prominent non-thermal sources, they are very likely responsible for the acceleration of the bulk of Galactic cosmic rays (CRS). To firmly establish the SNR paradigm for the origin of cosmic rays, it should be confirmed that protons are indeed accelerated in, and released from, SNRs with the appropriate flux and spectrum. This can be done by detailed theoretical models which account for microphysics of acceleration and various radiation processes of hadrons and leptons. The current generation of Cherenkov telescopes has insufficient sensitivity to constrain theoretical models. A new facility, the Cherenkov Telescope Array (CTA), will have superior capabilities and may finally resolve this long standing issue of high-energy astrophysics. We want to assess the capabilities of CTA to reveal the physics of various types of SNRs in the initial 2000 years of their evolution. During this time, the efficiency to accelerate cosmic rays is highest. We perform time-dependent simulations of the hydrodynamics, the magnetic fields, the cosmic-ray acceleration, and the non-thermal emission for type Ia, Ic and IIP SNRs. We calculate the CTA response to the y-ray emission from these SNRs for various ages and distances, and we perform a realistic analysis of the simulated data. We derive distance limits for the detectability and resolvability of these SNR types at several ages. We test the ability of CTA to reconstruct their morphological and spectral parameters as a function of their distance. Finally, we estimate how well CTA data will constrain the theoretical models. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Acceleration of particles
KW  - Gamma rays: General
KW  - ISM: Supernova remnants
KW  - Radiation mechanisms: Non-termal
Y1  - 2015
U6  - https://doi.org/10.1016/j.astropartphys.2014.08.005
SN  - 0927-6505
SN  - 1873-2852
VL  - 62
SP  - 152
EP  - 164
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Charpinet, Stéphane
A1  - Brassard, P.
A1  - Fontaine, G.
A1  - Van Grootel, Valerie
A1  - Zong, Weika
A1  - Giammichele, N.
A1  - Heber, Ulrich
A1  - Bognár, Zsófia
A1  - Geier, Stephan
A1  - Green, Elizabeth M.
A1  - Hermes, J. J.
A1  - Kilkenny, D.
A1  - Ostensen, R. H.
A1  - Pelisoli, Ingrid Domingos
A1  - Silvotti, R.
A1  - Telting, J. H.
A1  - Vuckovic, Maja
A1  - Worters, H. L.
A1  - Baran, Andrzej S.
A1  - Bell, Keaton J.
A1  - Bradley, Paul A.
A1  - Debes, J. H.
A1  - Kawaler, S. D.
A1  - Kolaczek-Szymanski, P.
A1  - Murphy, S. J.
A1  - Pigulski, A.
A1  - Sodor, A.
A1  - Uzundag, Murat
A1  - Handberg, R.
A1  - Kjeldsen, H.
A1  - Ricker, G. R.
A1  - Vanderspek, R. K.
T1  - TESS first look at evolved compact pulsators Discovery and asteroseismic probing of the g-mode hot B subdwarf pulsator EC 21494-7018
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Context. The TESS satellite was launched in 2018 to perform high-precision photometry from space over almost the whole sky in a search for exoplanets orbiting bright stars. This instrument has opened new opportunities to study variable hot subdwarfs, white dwarfs, and related compact objects. Targets of interest include white dwarf and hot subdwarf pulsators, both carrying high potential for asteroseismology. Aims. We present the discovery and detailed asteroseismic analysis of a new g-mode hot B subdwarf (sdB) pulsator, EC 21494-7018 (TIC 278659026), monitored in TESS first sector using 120-s cadence. Methods. The TESS light curve was analyzed with standard prewhitening techniques, followed by forward modeling using our latest generation of sdB models developed for asteroseismic investigations. By simultaneously best-matching all the observed frequencies with those computed from models, we identified the pulsation modes detected and, more importantly, we determined the global parameters and structural configuration of the star. Results. The light curve analysis reveals that EC 21494-7018 is a sdB pulsator counting up to 20 frequencies associated with independent g-modes. The seismic analysis singles out an optimal model solution in full agreement with independent measurements provided by spectroscopy (atmospheric parameters derived from model atmospheres) and astrometry (distance evaluated from Gaia DR2 trigonometric parallax). Several key parameters of the star are derived. Its mass (0.391 +/- 0.009x2006;M-circle dot) is significantly lower than the typical mass of sdB stars and suggests that its progenitor has not undergone the He-core flash; therefore this progenitor could originate from a massive (greater than or similar to 2;M-circle dot) red giant, which is an alternative channel for the formation of sdBs. Other derived parameters include the H-rich envelope mass (0.0037 +/- 0.0010;M-circle dot), radius (0.1694 +/- 0.0081;R-circle dot), and luminosity (8.2 +/- 1.1;L-circle dot). The optimal model fit has a double-layered He+H composition profile, which we interpret as an incomplete but ongoing process of gravitational settling of helium at the bottom of a thick H-rich envelope. Moreover, the derived properties of the core indicate that EC 21494-7018 has burnt similar to 43% (in mass) of its central helium and possesses a relatively large mixed core (M-core;=;0.198 +/- 0.010;M-circle dot), in line with trends already uncovered from other g-mode sdB pulsators analyzed with asteroseismology. Finally, we obtain for the first time an estimate of the amount of oxygen (in mass; X(O)(core) = 0.16(-0.05)(+0.13)X(O)core=0.16-0.05+0.13$ X(mathrm{O})_{mathrm{core}}=0.16_{-0.05}<^>{+0.13} $) produced at this stage of evolution by an helium-burning core. This result, along with the core-size estimate, is an interesting constraint that may help to narrow down the still uncertain C-12(alpha,;gamma)O-16 nuclear reaction rate.
KW  - asteroseismology
KW  - stars
KW  - interiors
KW  - oscillations
KW  - horizontal-branch
KW  - individual
KW  - TIC 278659026
KW  - subdwarfs
Y1  - 2019
U6  - https://doi.org/10.1051/0004-6361/201935395
SN  - 0004-6361
SN  - 1432-0746
VL  - 632
PB  - EDP Sciences
CY  - Les Ulis
ER  -