Muestra métricas de impacto externas asociadas a la publicación. Para mayor detalle:
| Indexado |
|
||||
| DOI | 10.1051/0004-6361/201936078 | ||||
| Año | 2020 | ||||
| Tipo | artículo de investigación |
Citas Totales
Autores Afiliación Chile
Instituciones Chile
% Participación
Internacional
Autores
Afiliación Extranjera
Instituciones
Extranjeras
We present the results from VLT/X-shooter spectroscopic observations of 11 extremely strong intervening damped Lyman-alpha absorbers (ESDLAs) that were initially selected as high N(HI) (i.e. >= 5 x 10(21) cm(-2)) candidates from the Sloan Digital Sky Survey (SDSS). We confirm the high HI column densities, which we measure to be in the range log N(HI) = 21.6 - 22.4. Molecular hydrogen is detected with high column densities (N(H-2) >= 10(18) cm(-2)) in 5 out of 11 systems, 3 of which are reported here for the first time, and we obtain conservative upper limits on N(H-2) for the remaining 6 systems. We also measure the column density of various metal species (ZnII, FeII, SiII, CrII, and CI), quantify the absorption-line kinematics (Delta v(90)), and estimate the extinction of the background quasar light (A(V)) by dust in the absorbing gas. We compare the chemical properties of this sample of ESDLAs, supplemented with literature measurements, to that of DLAs located at the redshift of long-duration gamma-ray bursts (GRB-DLAs). We confirm that the two populations are almost indistinguishable in terms of chemical enrichment and gas kinematics. In addition, we find no marked differences in the incidence of H-2. All this suggests that ESDLAs and GRB-DLAs probe similar galactic environments. We search for the galaxy counterparts of ESDLAs and find associated emission lines in 3 out of 11 systems, 2 of which are reported here for the first time (at z(abs) = 2.304 and 2.323 towards the quasars SDSS J002503.03+114547.80 and SDSS J114347.21+142021.60, respectively). The measured separations between the quasar sightlines and the emission associated with the ESDLA galaxy (for a total of five sightlines) are all very small (rho < 3 kpc). Because our observations are complete up to rho similar to 7 kpc, we argue that the emission counterparts of the remaining systems are more likely below the detection limit than outside the search area. While the small impact parameters are similar to what is observed for GRB-DLAs, the associated star formation rates are on average lower than for GRB host galaxies. This is explained by long-duration GRBs being associated with the death of massive stars and therefore pinpointing regions of active star formation in the GRB host galaxies. Our observations support the suggestion from the literature that ESDLAs could act as blind analogues of GRB-DLAs, probing neutral gas with high column density in the heart of high-redshift galaxies, without any prior on the instantaneous star formation rate.
| Ord. | Autor | Género | Institución - País |
|---|---|---|---|
| 1 | Ranjan, A. | - |
Inst Astrophys Paris - Francia
CNRS Centre National de la Recherche Scientifique - Francia |
| 2 | Noterdaeme, Pasquier | - |
Inst Astrophys Paris - Francia
CNRS Centre National de la Recherche Scientifique - Francia |
| 3 | Krogager, J. K. | Hombre |
Inst Astrophys Paris - Francia
CNRS Centre National de la Recherche Scientifique - Francia |
| 4 | Petitjean, P. | Hombre |
Inst Astrophys Paris - Francia
CNRS Centre National de la Recherche Scientifique - Francia |
| 5 | Srianand, Raghunathan | - |
Interuniv Ctr Astron & Astrophys - India
Inter-University Centre for Astronomy and Astrophysics India - India |
| 6 | Balashev, S. | Hombre |
Ioffe Inst - Rusia
Ioffe Institute - Rusia |
| 7 | Gupta, Neeraj | Hombre |
Interuniv Ctr Astron & Astrophys - India
Inter-University Centre for Astronomy and Astrophysics India - India |
| 8 | Ledoux, Cedric | Hombre |
ESO - Chile
European Southern Observatory Santiago - Chile European Southern Observ - Chile |
| Fuente |
|---|
| Russian Foundation for Basic Research |
| Agence Nationale de la Recherche |
| RFBR |
| French Agence Nationale de la Recherche |
| Indo-French Centre for the Promotion of Advanced Research |
| Indo-French Centre for the Promotion of Advanced Research (Centre Franco-Indien pour la Promotion de la Recherche Avancee) |
| Basis Foundation |
| IAP |
| Agradecimiento |
|---|
| We thank the anonymous referee for useful comments and suggestions that helped to improve the clarity of the manuscript. The authors are grateful to the European Southern Observatory (ESO) and in particular the Paranal observatory's sta ff for carrying out their observations in service mode. AR, PN, PPJ, RS, and NG gratefully acknowledge the support of the Indo-French Centre for the Promotion of Advanced Research (Centre Franco-Indien pour la Promotion de la Recherche Avancee) under contract no. 5504-2 (PIs Gupta and Noterdaeme). We also thank the Institut d'Astrophysique de Paris (IAP) and the Inter-University Centre for Astronomy and Astrophysics (IUCAA) for hospitality during visits to these institutes. The research leading to these results has received funding from the French Agence Nationale de la Recherche under grant no ANR-17-CE31-0011-01 (project "HIH2" - PI Noterdaeme). PN and JKK thank the ESO Science Visitor program for hospitality and support during their visit to the ESO headquarters in Chile. SAB is supported by RFBR (grant No. 18-02-00596). SAB also thanks the Basis foundation and the IAP for hospitality and financial support during the time part of this work was performed. |
| Acknowledgements. We thank the anonymous referee for useful comments and suggestions that helped to improve the clarity of the manuscript. The authors are grateful to the European Southern Observatory (ESO) and in particular the Paranal observatory’s staff for carrying out their observations in service mode. AR, PN, PPJ, RS, and NG gratefully acknowledge the support of the Indo-French Centre for the Promotion of Advanced Research (Centre Franco-Indien pour la Promotion de la Recherche Avancée) under contract no. 5504-2 (PIs Gupta and Noterdaeme). We also thank the Institut d’Astrophysique de Paris (IAP) and the Inter-University Centre for Astronomy and Astrophysics (IUCAA) for hospitality during visits to these institutes. The research leading to these results has received funding from the French Agence Nationale de la Recherche under grant no ANR-17-CE31-0011-01 (project “HIH2” – PI Noterdaeme). PN and JKK thank the ESO Science Visitor program for hospitality and support during their visit to the ESO headquarters in Chile. SAB is supported by RFBR (grant No. 18-02-00596). SAB also thanks the Basis foundation and the IAP for hospitality and financial support during the time part of this work was performed. |