J/ApJS/230/6 HST -COS & -STIS absorption-line spectroscopy. II. (Keeney+, 2017)
Characterizing the circumgalactic medium of nearby galaxies with HST/COS and
HST/STIS absorption-line spectroscopy.
II. Methods and models.
Keeney B.A., Stocke J.T., Danforth C.W., Shull J.M., Pratt C.T.,
Froning C.S., Green J.C., Penton S.V., Savage B.D.
<Astrophys. J. Suppl. Ser., 230, 6-6 (2017)>
=2017ApJS..230....6K 2017ApJS..230....6K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; QSOs ; Redshifts ; Spectra, ultraviolet
Keywords: galaxies: dwarf; galaxies: groups: general; galaxies: halos;
galaxies: spiral; intergalactic medium; quasars: absorption lines
Abstract:
We present basic data and modeling for a survey of the cool,
photoionized circumgalactic medium (CGM) of low-redshift galaxies
using far-UV QSO absorption-line probes. This survey consists of
"targeted" and "serendipitous" CGM subsamples, originally described in
Stocke+ (Paper I, 2013ApJ...763..148S 2013ApJ...763..148S). The targeted subsample probes
low-luminosity, late-type galaxies at z<0.02 with small impact
parameters (<ρ≥71kpc), and the serendipitous subsample probes
higher luminosity galaxies at z≲0.2 with larger impact parameters
(<ρ≥222kpc). Hubble Space Telescope and FUSE UV spectroscopy of
the absorbers and basic data for the associated galaxies, derived from
ground-based imaging and spectroscopy, are presented. We find broad
agreement with the COS-Halos results, but our sample shows no evidence
for changing ionization parameter or hydrogen density with distance
from the CGM host galaxy, probably because the COS-Halos survey probes
the CGM at smaller impact parameters. We find at least two passive
galaxies with HI and metal-line absorption, confirming the intriguing
COS-Halos result that galaxies sometimes have cool gas halos despite
no on-going star formation. Using a new methodology for fitting HI
absorption complexes, we confirm the CGM cool gas mass of Paper I, but
this value is significantly smaller than that found by the COS-Halos
survey. We trace much of this difference to the specific values of the
low-z metagalactic ionization rate assumed. After accounting for this
difference, a best-value for the CGM cool gas mass is found by
combining the results of both surveys to obtain
log(M/M☉)=10.5±0.3, or ∼30% of the total baryon reservoir of
an L≥L*, star-forming galaxy.
Description:
The 2009-2013 HST COS spectroscopy of many of these targets was
described in detail in Danforth+ (2016, J/ApJ/817/111). A detailed
discussion of the error analysis of these measurements can be found in
Keeney+ (2013ApJ...765...27K 2013ApJ...765...27K). The HST STIS (E140M data only) and FUSE
spectroscopy were described in detail in Tilton+ (2012, J/ApJ/759/112).
Only one of the targeted sight lines (PG 0832+251) was observed with
FUSE, but many of the serendipitous sight lines were.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 135 13 Targeted sample summary
table2.dat 134 35 Serendipitous sample summary
table3.dat 122 467 Multi-component absorption line fits
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See also:
VIII/73 : HI Parkes All Sky Survey Catalogue (HIPASS) (Meyer+, 2004)
VII/249 : 6dF-DR2 Galaxy Survey (Jones+, 2005)
VIII/77 : HI spectral properties of galaxies (Springob+, 2005)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJS/81/5 : Green Bank neutral hydrogen survey (Schneider+, 1992)
J/A+AS/114/527 : UV properties of normal galaxies. III. (Rifatto+, 1995)
J/ApJS/101/287 : H II Regions in Seyfert galaxies. I. (Tsvetanov+ 1995)
J/ApJ/508/200 : QSO low-z Lyα absorbers (Tripp+, 1998)
J/ApJ/519/1 : Lyman-break galaxies at z≳4 (Steidel+, 1999)
J/ApJ/559/654 : Lyα absorption systems. V. (Chen+, 2001)
J/ApJ/596/768 : Optical depths in 19 QSOs (Schaye+, 2003)
J/ApJ/617/718 : Atomic data and EW for PKS 0405-123 (Prochaska+, 2004)
J/AJ/130/873 : Properties of BQS objects in SDSS DR3 area (Jester+, 2005)
J/ApJ/679/194 : Low-z intergalactic medium. III. (Danforth+, 2008)
J/ApJS/178/247 : Hα and [NII] survey in local 11 Mpc (Kennicutt+, 2008)
J/ApJS/177/39 : Survey of low-redshift OVI absorbers (Tripp+, 2008)
J/ApJ/701/1219 : Galaxy survey in 3 QSO fields (Chen+, 2009)
J/ApJ/716/1514 : Galaxies as tracers of the circumgalactic gas (Yao+, 2010)
J/ApJS/193/28 : Galaxy survey around 20 UV-bright quasars (Prochaska+, 2011)
J/ApJ/740/91 : Lyα & OVI in galaxies around QSOs (Prochaska+, 2011)
J/ApJ/759/112 : The UV low-redshift intergalactic medium (Tilton+, 2012)
J/MNRAS/434/1765 : Catalog of galaxies around PKS 0405-123 (Johnson+, 2013)
J/MNRAS/444/527 : Tully-Fisher distances for Spitzer galaxies (Sorce+, 2014)
J/ApJ/804/79 : HST/COS obs. of QSOs within 600kpc of M31 (Lehner+, 2015)
J/ApJ/815/91 : z<0.16 CIV absorbers from HST/COS (Burchett+, 2015)
J/ApJ/817/111 : HST/COS survey of z<0.9 AGNs. I. (Danforth+, 2016)
Byte-by-byte Description of file: table[12].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- Line QSO sight line identifier
19- 42 A24 --- Gal Associated galaxy identifier
44- 48 I5 km/s cz1 [654/52914] First value of absorber velocity
(czabs)
50- 54 I5 km/s cz2 ? Second value of czabs
56- 60 I5 km/s cz3 ? Third value of czabs
62- 66 I5 km/s cz4 ? Fourth value of czabs
68- 72 I5 km/s cz5 ? Fifth value of czabs
74- 78 I5 km/s cz6 ? Sixth value of czabs
80- 89 A10 --- Inst Instrument(s) used for the absorber detections
91- 95 I5 km/s czgal [649/52873] Galaxy's recession velocity (czgal)
97-101 F5.3 Lsun Lum [0.003/3.5] Rest-frame g-band galaxy luminosity (1)
102 A1 --- u_Lum Uncertainty flag on Lum
104-106 I3 kpc rho [7/505] Impact parameter (ρ)
108-110 I3 kpc Rvir [47/275] Virial radius (Rvir)
111 A1 --- u_Rvir Uncertainty flag on Rvir
113-116 F4.2 --- r/R [0.1/2.1] Ratio of impact parameter to Rvir
117 A1 --- u_r/R Uncertainty flag on r/R
119 A1 --- l_eta Limit flag on eta
120-123 F4.2 --- eta [0.02/4.3] ηρ ratio (2)
125-128 F4.2 --- eVir [0.02/4]? ηvir ratio (3)
129 A1 --- u_eVir Uncertainty flag on eVir
131-134 F4.2 --- eDelv [0.01/6.8]? ηΔv ratio (4)
135 A1 --- u_eDelv Uncertainty flag on eDelv
--------------------------------------------------------------------------------
Note (1): The rest-frame g-band galaxy luminosity in L* units (we adopt
Mg*=-20.3, the value of Montero-Dorta & Prada 2009MNRAS.399.1106M 2009MNRAS.399.1106M
at h=0.7).
Note (2): The ratio of the impact parameter (in kpc) of the tabulated galaxy to
that of the next-nearest galaxy:
ηρ=ρng/ρnng.
Note (3): The ratio of the normalized impact parameter of the tabulated galaxy
to that of the next-nearest galaxy:
ηvir=(ρ/Rvir)ng/(ρ/Rvir)nng.
Note (4): The ratio of the normalized absorber-galaxy velocity difference of
the tabulated galaxy to that of the next-nearest galaxy:
ηΔv=(|Δv|/vesc)ng/(|Δv|/vesc)nng.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/187] System identifier
5- 21 A17 --- Line Sight line identifier
23- 28 A6 --- Ion Ion identifier
30- 34 I5 km/s cz [643/52945]? Redshift from absorption line
36- 40 F5.1 km/s b [4/128]? Doppler b-value
41 A1 --- u_b Uncertainty flag on b
43- 46 F4.1 km/s e_b [0/57]? Uncertainty in b
48 A1 --- l_logN Limit flag on logN
50- 54 F5.2 [cm-2] logN [11.6/18.4]? Log number abundance
55 A1 --- u_logN Uncertainty flag in logN
57- 60 F4.2 [cm-2] e_logN [0.01/3]? Uncertainty in logN
62-122 A61 --- Comm Additional comments
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History:
From electronic version of the journal
References:
Stocke et al. Paper I. 2013ApJ...763..148S 2013ApJ...763..148S
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Jun-2017