Table · dataset · 2023
GRB hydrogen column densities
Listed in IVOA Registry (Virtual Observatory)
It is known that the GRB equivalent hydrogen column density (N_HX_) changes with redshift and that, typically, N_HX_ is greater than the GRB host neutral hydrogen column density.
Description
We have compiled a large sample of data for GRB N_HX_ and metallicity [X/H]. The main aims of this paper are to generate improved N_HX_ for our sample by using actual metallicities, dust corrected where available for detections, and for the remaining GRB, a more realistic average intrinsic metallicity using a standard adjustment from solar.
Then, by approximating the GRB host intrinsic hydrogen column density using the measured neutral column (N_HI,IC_) adjusted for the ionization fraction, we isolate a more accurate estimate for the intergalactic medium (IGM) contribution. The GRB sample mean metallicity is =-1.17+/-0.09 rms (or 0.07+/-0.05 Z/Z_sol_) from a sample of 36 GRB with a redshift 1.76<=z<=5.91, substantially lower than the assumption of solar metallicity used as standard for many fitted N_HX_.
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Lower GRB host mean metallicity results in increased estimated N_HX_ with the correction scaling with redshift as {Delta}log(N_HX_cm^-2^)=(0.59+/-0.04)log(1+z)+0.18+/-0.02. Of the 128 GRB with data for both N_HX_ and N_HI,IC_ in our sample, only six have N_HI,IC_>N_HX_ when revised for realistic metallicity, compared to 32 when solar metallicity is assumed. The lower envelope of the revised N_HX_-N_HI,IC_, plotted against redshift can be fit by log(N_HX_-N_HI,IC_cm^-2^)=20.3+2.4log(1+z).
This is taken to be an estimate for the maximum IGM hydrogen column density as a function of redshift. Using this approach, we estimate an upper limit to the hydrogen density at redshift zero (n_0_) to be consistent with n_0_=0.17x10^-7^cm^-3^.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/495/2342 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2020MNRAS.495.2342D ui.adsabs.harvard.edu/abs/2020MNRAS.495.2342D ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/mnras/495/2342 ↗
catalogue entry · from IVOA Registry
Topics
- From keywords
- Astronomy & Astrophysics
Provenance · 1 source records, 10 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/mnras/495/2342 | 15 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:gamma-ray | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:radio | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:x-ray | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |