J/ApJ/923/189 18 UV bright QSOs obs. with HST (COS-IGrM survey) (McCabe+, 2021)
Detection of a multiphase intragroup medium: results from the COS-IGrM survey.
McCabe T., Borthakur S., Heckman T., Tumlinson J., Bordoloi R., Dave R.
<Astrophys. J., 923, 189 (2021)>
=2021ApJ...923..189M 2021ApJ...923..189M
ADC_Keywords: Galaxies, group; QSOs; Spectra, ultraviolet; Redshifts;
Velocity dispersion; Equivalent widths; Intergalactic medium
Keywords: Galaxy groups ; Quasar absorption line spectroscopy
Abstract:
We present the results of the Cosmic Origins Spectrograph-Intragroup
Medium (COS-IGrM) Survey that used the COS on the Hubble Space
Telescope to observe a sample of 18 UV bright quasars, each probing
the IGrM of a galaxy group. We detect Lyα, CII, NV, SiII, SiIII,
and OVI in multiple sightlines. The highest ionization species
detected in our data is OVI, which was detected in eight out of
18 quasar sightlines. The wide range of ionization states observed
provide evidence that the IGrM is patchy and multiphase. We find that
the OVI detections generally align with radiatively cooling gas
between 105.8 and 106K. The lack of OVI detections in 10 of the
18 groups illustrates that OVI may not be the ideal tracer of the
volume filling component of the IGrM. Instead, it either exists at
trace levels in a hot IGrM or is generated in the boundary between the
hotter IGrM and cooler gas.
Description:
The Cosmic Origins Spectrograph-Intragroup Medium (COS-IGrM) sample is
composed of 18 galaxy groups each with a background QSO with a GALEX
far-ultraviolet (FUV) magnitude brighter than 19. The sample was
created by cross referencing the Tago+ (2010, J/A+A/514/A102) galaxy
group catalog with the catalog of unique GALEX Data Release 5 QSOs
(Bianchi+ 2011, J/MNRAS/411/2770).
The 18 QSOs in our sample were observed with the G130M grating of the
Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope.
Data for 16 of the QSO sightlines were obtained under program 13314,
while the remaining were obtained through archival data. The
observations were designed to achieved a signal-to-noise ratio (S/N)
greater than 10 per resolution element for each sightline. The spectra
covered a observed frame wavelength from 1070-1465Å corresponding
to a rest-frame wavelength range of 946-1295Å for the median
redshift of the sample of z=0.1311.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 18 The Cosmic Origins Spectrograph-Intragroup Medium
(COS-IGrM) sample
table2.dat 114 181 Absorption line measurements within ±800km/s
of Group Center
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJS/155/351 : Absorption toward PG 1116+215 (Sembach+, 2004)
J/ApJS/168/213 : Ionization states and cooling efficiencies (Gnat+, 2007)
J/ApJS/176/59 : FUSE survey of OVI in the disk of the MW (Bowen+, 2008)
J/ApJS/177/39 : Survey of low-redshift OVI absorbers (Tripp+, 2008)
J/A+A/514/A102 : SDSS DR7 groups of galaxies (Tago+, 2010)
J/MNRAS/411/2770 : Hot white dwarfs in GALEX-DR5 (Bianchi+, 2011)
J/ApJ/791/128 : Galaxy data for spiral-rich group members (Stocke+, 2014)
J/ApJ/815/91 : z<0.16 CIV absorbers from HST/COS QSOs sp. (Burchett+, 2015)
J/ApJ/804/79 : HST/COS obs. of QSOs within 600kpc of M31 (Lehner+, 2015)
J/A+A/590/A68 : AGN data and absorption-line measurements (Richter+, 2016)
J/MNRAS/490/1451 : MUDF properties of gal. groups at 0.5<z<1.5 (Fossati+, 2019)
J/ApJS/240/15 : HST/COS UV obs. of low-z SDSS galaxy groups (Stocke+, 2019)
J/ApJ/892/102 : XMM X-ray data of Planck ESZ gal. clusters (Lovisari+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/18] Running sequence number
4- 13 A10 --- Group Galaxy group name
15- 21 F7.3 deg RAdeg [130.49/244.43] Group right ascension (J2000)
22- 28 F7.3 deg DEdeg [5.29/56.92] Group declination (J2000)
30- 35 F6.4 --- zGp [0.074/0.164] Group redshift
37- 43 F7.3 deg RAQdeg [130.49/244.35] QSO right ascension (J2000)
45- 50 F6.3 deg DEQdeg [5.35/56.97] QSO declination (J2000)
52- 57 F6.4 --- zQSO [0.086/1.36] Redshift of the quasar
59 I1 --- Ngp [3/7] Number of galaxies in the group Ngp
61- 65 F5.1 km/s sigT10 [43/243] Velocity dispersion
(Tago+ 2010, J/A+A/514/A102)
67- 69 I3 kpc RvirT10 [291/777] Virial radius
(Tago+ 2010, J/A+A/514/A102)
71- 73 I3 kpc rho [95/926] QSO impact parameter ρQSO
75- 79 F5.2 [Msun] logMhalo [12.85/13.61] Log of halo mass
81- 83 I3 kpc Rvir [396/709] Virial radius
85- 87 I3 km/s sigGp [160/287] Group velocity dispersion
89- 95 F7.3 deg RACdeg [130.5/244.4] Closest member galaxy to the
QSO sightline right ascension (J2000)
97- 102 F6.3 deg DECdeg [5.3/57] Closest member galaxy to the QSO
sightline declination (J2000)
104- 111 A8 --- sSet Subset
113- 114 I2 --- Fig2 [1/12]? Figure 2 subset number;
column added by CDS
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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- 10 A10 --- Group Galaxy group name
12- 17 F6.4 --- z [0.075/0.164] Redshift of group
19- 24 A6 --- Sp Ionization species
28- 31 I4 0.1nm Wave [1025/1260] Ionization species rest wavelength;
Angstrom
32 A1 --- f_Wave [abc] Flag on Wave (1)
35 I1 --- Comp [1/5]? Component Number (2)
38- 45 F8.3 10-13m EW [-37/1603]? Equivalent Width; milli-Angstroms (3)
48- 54 F7.4 10-13m e_EW [3.8/57]? Uncertainty in equivalent width (4)
57- 64 F8.3 km/s Vel [-753/881]? Observed velocity (5)
66- 71 F6.3 km/s e_Vel [0.9/94]? Uncertainty in observed velocity (5)
74- 80 F7.4 cm-2 logN [11.8/18.4]? Log10 column density (3)
83- 88 F6.4 cm-2 e_logN [0.02/1]? Uncertainty in log10 column density (4)
91- 97 F7.3 km/s b [4.3/146]? Doppler b parameter (5)
99-105 F7.3 km/s E_b [1.4/130]? Upper uncertainty in b (5)
108-114 F7.4 km/s e_b [1.4/61]? Lower uncertainty in b (5)
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Note (1): Flag as follows:
a = There is no COS coverage of Si II 1260 at the observed wavelength.
b = C II is blended with Milky Way Si II 1193, which was modeled and
removed. Since the Milky Way Si II line was saturated, the current
data do not allow for all C II absorption to be measured.
c = There is no COS coverage of N V 1238 at the observed wavelength.
Note (2): The component number indicates the individual absorption
component for blended features.
Note (3): If components are blended, the EQ is for all blended components.
Note (4): No data indicates an upper limit for a non-detection.
Note (5): No data indicates a non-detection.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-May-2023