English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
 
 
DownloadE-Mail
  New constraints on the physical conditions in H2-bearing GRB-host damped Lyman-α absorbers

Heintz, K. E., Bolmer, J., Ledoux, C., Noterdaeme, P., Krogager, J.-K., Fynbo, J. P. U., et al. (2019). New constraints on the physical conditions in H2-bearing GRB-host damped Lyman-α absorbers. Astronomy and Astrophysics, 629: A131. doi:10.1051/0004-6361/201936250.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0005-4ADC-1 Version Permalink: http://hdl.handle.net/21.11116/0000-0005-4ADD-0
Genre: Journal Article

Files

show Files
hide Files
:
New constraints on the physical conditions in H2-bearing GRB-host damped Lyman-α absorbers.pdf (Any fulltext), 5MB
 
File Permalink:
-
Name:
New constraints on the physical conditions in H2-bearing GRB-host damped Lyman-α absorbers.pdf
Description:
-
Visibility:
Private
MIME-Type / Checksum:
application/pdf
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Heintz, K. E., Author
Bolmer, J.1, Author              
Ledoux, C., Author
Noterdaeme, P., Author
Krogager, J.-K., Author
Fynbo, J. P. U., Author
Jakobsson, P., Author
Covino, S., Author
D’Elia, V., Author
Pasquale, M. De, Author
Hartmann, D. H., Author
Izzo, L., Author
Japelj, J., Author
Kann, D. A., Author
Kaper, L., Author
Petitjean, P., Author
Rossi, A., Author
Salvaterra, R., Author
Schady, P.1, Author              
Selsing, J., Author
Starling, R., AuthorTanvir, N. R., AuthorThöne, C. C., Authorde Postigo, A. Ugarte, AuthorVergani, S. D., AuthorWatson, D., AuthorWiersema, K., AuthorZafar, T., Author more..
Affiliations:
1High Energy Astrophysics, MPI for Extraterrestrial Physics, Max Planck Society, ou_159890              

Content

show
hide
Free keywords: -
 Abstract: We report the detections of molecular hydrogen (H2), vibrationally-excited H2 (H2∗), and neutral atomic carbon (C I), an efficient tracer of molecular gas, in two new afterglow spectra of GRBs 181020A (z = 2.938) and 190114A (z = 3.376), observed with X-shooter at the Very Large Telescope (VLT). Both host-galaxy absorption systems are characterized by strong damped Lyman-α absorbers (DLAs) and substantial amounts of molecular hydrogen with logN(H I, H2) = 22.20 ± 0.05,  20.40 ± 0.04 (GRB 181020A) and logN(H I, H2) = 22.15 ± 0.05,  19.44 ± 0.04 (GRB 190114A). The DLA metallicites, depletion levels, and dust extinctions are within the typical regimes probed by GRBs with [Zn/H] = −1.57 ± 0.06, [Zn/Fe] = 0.67 ± 0.03, and AV = 0.27 ± 0.02 mag (GRB 181020A) and [Zn/H] = −1.23 ± 0.07, [Zn/Fe] = 1.06 ± 0.08, and AV = 0.36 ± 0.02 mag (GRB 190114A). In addition, we examine the molecular gas content of all known H2-bearing GRB-DLAs and explore the physical conditions and characteristics required to simultaneously probe C I and H2∗. We confirm that H2 is detected in all C I- and H2∗-bearing GRB absorption systems, but that these rarer features are not necessarily detected in all GRB H2 absorbers. We find that a large molecular fraction of fH2 ≳ 10−3 is required for C I to be detected. The defining characteristic for H2∗ to be present is less clear, though a large H2 column density is an essential factor. We also find that the observed line profiles of the molecular-gas tracers are kinematically “cold”, with small velocity offsets of δv <  20 km s−1 from the bulk of the neutral absorbing gas. We then derive the H2 excitation temperatures of the molecular gas and find that they are relatively low with Tex ≈ 100−300 K, however, there could be evidence of warmer components populating the high-J H2 levels in GRBs 181020A and 190114A. Finally, we demonstrate that even though the X-shooter GRB afterglow campaign has been successful in recovering several H2-bearing GRB-host absorbers, this sample is still hampered by a significant dust bias excluding the most dust-obscured H2 absorbers from identification. C I and H2∗ could open a potential route to identify molecular gas even in low-metallicity or highly dust-obscured bursts, though they are only efficient tracers for the most H2-rich GRB-host absorption systems.

Details

show
hide
Language(s):
 Dates: 2019-09-16
 Publication Status: Published online
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1051/0004-6361/201936250
Other: LOCALID: 3180089
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Astronomy and Astrophysics
  Other : Astron. Astrophys.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: France : EDP Sciences S A
Pages: - Volume / Issue: 629 Sequence Number: A131 Start / End Page: - Identifier: ISSN: 1432-0746
CoNE: https://pure.mpg.de/cone/journals/resource/954922828219_1