J/A+A/468/807 Redshifts of galaxies associated with X emission (Mannucci+, 2007)
A galaxy overdensity at z=0.401 associated with an X-ray emitting structure of
warm-hot intergalactic medium.
Mannucci F., Bonnoli G., Maiolino R., Zappacosta L., Pedani M.
<Astron. Astrophys. 468, 807 (2007)>
=2007A&A...468..807M 2007A&A...468..807M
ADC_Keywords: Galaxies, photometry ; X-ray sources ; Redshifts
Keywords: galaxies: intergalactic medium - galaxies: distances and redshifts -
X-rays: diffuse background
Abstract:
We present the results of spectroscopic observations of galaxies
associated with the diffuse X-ray emitting structure discovered by
Zappacosta et al. (2002A&A...394....7Z 2002A&A...394....7Z). After measuring the redshifts
of 161 galaxies, we confirm an overdensity of galaxies with projected
dimensions of at least 2Mpc, determine its spectroscopic redshift in
z=0.401±0.002, and show that it is spatially coincident with the
diffuse X-ray emission. This confirms the original claim that this
X-ray emission has an extragalactic nature and is due to the warm-hot
intergalactic medium (WHIM). We used this value of the redshift to
compute the temperature of the emitting gas. The resulting value
depends on the metallicity that is assumed for the IGM, and is
constrained to be between 0.3 and 0.6keV for metallicities between
0.05 and 0.3solar, in good agreement with the expectations from the
WHIM.
Description:
List of the target galaxies observed with the WHT/AF2/WYFOOS and
TNG/DOLORES multi-object spectrographs. For each galaxy, the
coordinates, the R-band magnitude, the spectroscopic redshift and
the spectral classification are given. Target galaxies have been
selected to have R-band magnitudes between 20.0 and 21.5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 57 269 Target list and spectroscopic redshift
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 d Seq Sequential number
8- 9 I2 h RAh Right ascension (J2000)
11- 12 I2 min RAm Right ascension (J2000)
14- 18 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
35- 38 F4.1 mag Rmag R-band magnitude (Vega system)
41- 43 A3 --- Tel [WHT TNG] Telescope (1)
46- 51 F6.4 --- z ? Spectroscopic redshift
54 I1 --- q_z [1/4]? Redshift quality flag (2)
57 A1 --- Class [EMLUQS] Spectral classification (3)
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Note (1): Telescope as follows:
WHT = Whilliam Hershel Telescope, AF2/WYFFOS
TNG = Telescopio Nazionale Galileo, DOLORES
Note (2): Redshift quality flag as follows:
1 = certain
2 = reliable
3 = uncertain
4 = tentative
Note (3): Spectral classification as follows:
E = Early type galaxy
M = intermediate type galaxy
L = late type galaxy
U = unclassified
Q = QSO
S = Galactic star
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Acknowledgements:
Filippo Mannucci, filippo(at)arcetri.astro.it
(End) Filippo Mannucci [INAF-IRA], Patricia Vannier [CDS] 10-Apr-2007