J/A+A/607/A107 GRB 080810 Keck/HIRES spectrum (Wiseman+, 2017)
Gas inflow and outflow in an interacting high-redshift galaxy.
The remarkable host environment of GRB 080810 at z = 3.35.
Wiseman P., Perley D. A., Schady P., Prochaska J. X., de Ugarte Postigo A.,
Kruehler T., Yates R. M., Greiner J
<Astron. Astrophys. 607, A107 (2017)>
=2017A&A...607A.107W 2017A&A...607A.107W (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; Spectroscopy
Keywords: galaxies: evolution - galaxies: interactions -
gamma-ray burst: individual: 080810
Abstract:
We reveal multiple components of an interacting galaxy system at
z∼3.35 through a detailed analysis of the exquisite high-resolution
Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB).
Through Voigt-profile fitting of absorption lines from the
Lyman-series, we constrain the neutral hydrogen column density
to NHI≤1018.35cm-2 for the densest of four distinct systems at
the host redshift of GRB 080810, among the lowest NHI ever observed in
a GRB host, despite the line of sight passing within a projected 5kpc
of the galaxy centres. By detailed analysis of the corresponding metal
absorption lines, we derive chemical, ionic and kinematic properties
of the individual absorbing systems, and thus build a picture of the
host as a whole. Striking differences between the systems imply that
the line of sight passes through several phases of gas: the
star-forming regions of the GRB host; enriched material in the form of
a galactic outflow; the hot and ionised halo of a second, interacting
galaxy falling towards the host at a line-of-sight velocity of
700km/s; and a cool, metal-poor cloud which may represent one of the
best candidates yet for the inflow of metal-poor gas from the
intergalactic medium.
Description:
On 2008-08-10 at T0=13:10:12 UT, the Burst Alert Telescope on board
Swift triggered on GRB 080810 2008), which at T0+80s was detected as
a bright source in Swift's X-ray Telescope (XRT) and Ultra-violet
and Optical Telescope (UVOT).
Starting 37.6 minutes after the trigger at 13:47:50 UT, GRB 080810 was
observed with the High Resolution Echelle Spectrometer (HIRES) mounted
on the 10-metre Keck I telescope of the W. M Keck Observatory located
at the summit of Mauna Kea, Hawaii. A series of two exposures of 1000
s each were taken using the C5 decker, providing a FWHM spectral
resolution of ∼8km/s.
The normalised reduced Keck/HIRES spectrum of GRB 080810 in ASCII
format. The respective FITS header appears first, and is commented out
with #.
Objects:
-------------------------------------------------------------
RA (2000) DE Designation(s)
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23 47 10.48 +00 19 11.3 GRB 080810 = Fermi bn080810549
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 124 1 Information on spectrum file
spectrum.dat 45 173311 GRB 080810 normalised reduced Keck/HIRES spectrum
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Name
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs Declination (J2000)
36- 41 I6 --- Nx Number of points
43- 51 F9.4 0.1nm blambda Lower value of wavelength interval
53- 61 F9.4 0.1nm Blambda Upper value of wavelength interval
63- 74 A12 --- FileName Name of the spectrum file
76-124 A49 --- Title Title of the file
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Byte-by-byte Description of file (#): spectrum.dat
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Bytes Format Units Label Explanations
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8- 16 F9.4 0.1nm lambda [3458.2153/7818.0631] Wavelength
19- 32 E14.10 --- NFlux Normalised flux
37- 45 F9.7 --- e_NFlux Normalised flux error
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Acknowledgements:
Philip Wiseman, wiseman(at)mpe.mpg.de
(End) Philip Wiseman [MPE], Patricia Vannier [CDS] 25-Jul-2017