QSO ABSORPTION LINE STUDIES
with the HUBBLE SPACE TELESCOPE
COLORADO GROUP: JOHN STOCKE, MIKE
SHULL, JAMES GREEN, STEVE PENTON,
CHARLES DANFORTH, BRIAN KEENEY
Results thus far based on:
DLA @
> 300 QSO ABSORBERS found by HST
Spectrographs at z < 0.1 and at low
column densities (NH I = 1012.5—16.5 cm-2 )
AND
>1.35 Million galaxy locations and
redshifts from the CfA galaxy redshift
survey, 2DF/6DF, SLOAN Digital Sky
Spectroscopic Survey (DR-6), FLASH
& others, including our own pencil-beam
Surveys in progress
cz=5250
km/s in UV
and H I
21cm
spectra of
PKS 1327206
QSO ABSORPTION LINE STUDIES
with the HUBBLE SPACE TELESCOPE
COLORADO GROUP: JOHN STOCKE, MIKE
SHULL, JAMES GREEN, STEVE PENTON,
CHARLES DANFORTH, BRIAN KEENEY
Results thus far based on:
> 300 QSO ABSORBERS found by HST
Spectrographs at z < 0.1 and at low
column densities (NH I = 1012.5—16.5 cm-2 )
AND
>1.35 Million galaxy locations and
redshifts from the CfA galaxy redshift
survey, 2DF/6DF, SLOAN Digital Sky
Spectroscopic Survey (DR-6), FLASH
& others, including our own pencil-beam
Surveys in progress
H II
regions
in red
in ESO
G13272041
Ly reveals H I not visible @ redshifted 21cm emission or absorption lines
??
SUMMARY OF STATISTICAL RESULTS
•
COSMIC BARYON CENSUS: Ly / baryon = 29 ± 4 % (most of the mass is in NHI < 10 13
cm-2 absorbers)
•
ASSOCIATION WITH GALAXIES? 78% LOCATED IN SUPERCLUSTER FILAMENTS;
22% IN VOIDS. STRONGER absorbers at NH I > 1013 cm-2 are more closely ASSOCIATED
WITH GALAXIES; WEAKER absorbers are more UNIFORMLY DISTRIBUTED in space.
•
b(voids) / b = 4.5 ±1.5% AS PREDICTED BY SIMULATIONS (Gottlober et al 2003).
Metallicity < 1.5% Solar (Stocke et al. 2007, ApJ, 671, 146)
•
At least 55% of all Ly absorbers with NH I > 1013 cm-2 are METAL-BEARING at ~ 10%
SOLAR. A typical galaxy filament is covered >50% by metal-enriched gas
•
Metal-bearing absorbers show spread of metals of 150—800h-170 kpc from the nearest
L* galaxy (23 absorbers in complete sample) and 50—450 h-170 kpc from the nearest
0.1L* galaxy (9 absorbers in complete sample) based on OVI and CIII (C IV, Si III
accounting and covering factor measurements in progress)
•
For details see PENTON et al. (2000a,b, 2002, 2004) ApJ (Ly alpha absorbers) and
STOCKE et al. (2006) ApJ 641, 217 . (OVI and C III absorbers with FUSE)
Impact Parameters Required to reproduce the Observed OVI dN/dz
(covering factor = 0.5; all galaxies of luminosity > L contribute)
Figure from
Tumlinson & Fang
2005 ApJL 623, L97
O VI maximum impact
parameters from
Stocke et al. 2007
Apj, 671, 146
Sample Sizes =
23
(of metal-enriched absorbers)
9
EXAMPLES of
ABSORBER
..DWARF
GALAXY PAIRS
KEENEY et al
In prep.
Dwarf Galaxy
Winds May Be the
largest contributor
to IGM metal
enrichment
Dwarf Galaxy Winds
Reproduced from Stocke et al. 2004, ApJ, 609, 94.
Reproduced from Keeney et al. 2006, AJ, 132,
2496
3C 273 / 0.004 L* Dwarf
SBS 1122+594 / IC 691 (0.06 L*)
Dwarf galaxies produce unbound winds!
SBS 1122+594 / IC 691ABSORBER/GALAXY
CONNECTIONS
IC 691: H I 21 cm
SDSS J112625.97+591737.5
czabs
czgal = 1204 ± 3 km/s
IC 691
czabs(CIV) = 1110 ± 30
km/s
NHI ~ 1015 cm-2
vesc(r>33kpc) 35 km/s
from Keeney et al. 2006, AJ, 132, 2496
SPECTRUM OF DWARF IS POST-STARBURST
Complete Blow Out then fading to
become Dwarf Spheroidal? “Cheshire Cat
Galaxy” (Charlton, 1995)
[Z]= -1±0.5; AGE=3.5±1.5 Gyrs
3C 273 Absorber/Galaxy Connections
3C 273 Absorber
cz= 1586 ± 5 km/s
NHI = 7 x 1015 cm2
n = 1.4 x 103 cm3
Shell thickness = 70 pc
Shell mass < 108 M
(if centered on dwarf)
[Fe/H] = 1.2
[Si/C] = +0.2
Dwarf Spheroidal Galaxy
cz = 1635 ± 50 km/s
b= 71 h170 kpc
mB = 17.9
MB = 13.9
L ~ 6 x 107 L ~ 0.004 L*
MHI < 3 x 106 M
[Fe/H] = 1
Mean Stellar Age = 2-5 Gyrs
STARBURST(S) totaling > 0.3 M yr1 for ~108 yrs at a time 2-5
Gyrs ago had sufficient SN energy to expel > 3 X 107 M of gas at
20-30 km s1 to ~100 kpc and so create the 3C 273 absorber.
VOID
VOID
VOID
FILAMENT
GASEOUS FILAMENT
COSMIC ORIGINS SPECTROGRAPH: TO BE INSTALLED
DURING SERVICING MISSION #4 IN SEPTEMBER 2008
Observational Goals Include:
Massive Starburst Galaxy Winds
(3 QSO/galaxy pairs)
Dwarf and LSB Galaxy winds
(6 QSO/galaxy pairs)
Normal Luminous Galaxy Halos
(3 QSOs around one L* galaxy)
“Cosmic Tomography” of the Great Wall
(6 QSO sightlines in 30 Mpc2 region
BL Lac Targets to search for Broad Ly
(7 targets totaling z 1.5)
Bright, long pathlength targets
(entire GTO target set yields z 15)
PI: James Green, U of Colorado
WHAT WILL BE DONE WHEN THE ``COSMIC ORIGINS
SPECTROGRAPH’’ IS INSTALLED NEXT YEAR ON HST
he Extent, Metallicity and Kinematics of a Normal, Luminous (~L*) Spiral Galaxy Using
multiple QSO sightlines
IGM: The InterGalactic Medium Explorer
tracing the Baryons from Cosmic Web to Galaxy Halo
Science Payloads:
#1: Long-Slit Diffuse Spectrograph
Ly and O VI 1031Å at /=2000
Slit: 1 x 20 arcminutes
Sensitivity: 25 photon units in deep,
multi-day pointings at z=0—0.1.
#2: NUV Camera: 2150-2350Å band
33 arcmin FOV; 3 arcsec resolution
MAB = 30.8 arcsec-2 in deep pointing
for 6 arcsec sized object
#3: FUV Camera: 900-1000Å band
MAB = 27.6 arcsec-2 in deep pointing
for 6 arcsec sized object
PI: James Green,
U of Colorado
MEDIAN DISTANCE TO NEAREST
> 0.1L* GALAXY
Sample
Name
Distance in
h-170 kpc
Sample
Size
• L* Galaxies :
350
500
• O VI Absorbers :
290
23
• Stronger half Ly Sample :
450
69
• Weaker half Ly Sample :
1850
69
----------------------------------------------------------------------------• Simulations of WHIM GAS :
200
Dave’ et al
• Simulations of Photo-ionized Gas: 1200
(1999)
• Data from Stocke et al. 2006 ApJ 641, 217