d. b. sanders institute for astronomy, university of hawaii
DESCRIPTION
The Dusty and Molecular Universe: A prelude to HERSCHEL and ALMA, 27-29 Oct, 2004, Paris. Starbursts and ULIRGs. Gas-Rich Mergers and the origin of nuclear starbursts and AGN. D. B. Sanders Institute for Astronomy, University of Hawaii. OUTLINE. IR Galaxies: SEDs, LF (vs.z) - PowerPoint PPT PresentationTRANSCRIPT
D. B. Sanders Institute for Astronomy,
University of Hawaii
Gas-Rich Mergers and the origin of nuclear starbursts and AGN
The Dusty and Molecular Universe: A prelude to HERSCHEL and ALMA, 27-29 Oct, 2004, Paris
Starbursts and ULIRGs
• IR Galaxies: SEDs, LF (vs.z)
• Origin & Evolution of LIGs/ULIGs• ULIGs: Superstarbursts and AGN• ULIGs and QSOs
OUTLINE
IRAS - ISO - SCUBA - MAMBO(1984) (1996) (1997) (1999) z <0.3 z < 1.5 z < 5-6 ?
SIRTF+AstroF - Herschel - ALMA (2003) (2006) (2008) (2010) z = 0-10?
Two IRAS All-Sky Surveys:
IRAS Revised Bright Galaxy Sample (RBGS:S60>5.24Jy)
638 Galaxies
IRAS 1-Jy ULIG Sample (1-Jy: S60>1.0Jy,Lir > 1012 Lsun)
118 Galaxies
Radio-to-UV SEDs of IRAS Selected Galaxies
“Infrared Galaxies” (f)IR / (f)opt > 1
638 Galaxies: f((60m) > 5 Jy118 ULIGs: f((60m) > 1 Jy
Galaxy Luminosity Functions
LFIR high luminosity tail:
L-2.35
(z) (1+z)5-8 3.5
(z <0.2) ~ 0.008 deg-2
slope = -1
The Hubble Deep Field (The opt/UV view)
SCUBA 850m
The FIR/submm view
kindly provided by Helmut Dannerbauer
ULIGs @ z ~ 2 – 4
f850 ~ 1 – 10 mJy
m K ~ 20 – 24 m I ~ 24 – 30 m B ~ 26 – 33
ULIGs at High Redshift
Galaxy Luminosity Functions
Z=0.40
Z=0.80
Z=0.13
Z=0.045
Z ~2.4
slope= -1
The “Star Formation Rate” versus Redshift
Luminous Infrared Galaxies
The Origin and Evolution of
Strong Interactions/Mergers of Molecular Gas-rich Disks
IRAS RBGS Optical Images of LIGs
Log LIR = 11.66 - 11.99
Ishida, ApJL (2003)
Log LIR = 11.10 - 11.48
IRAS RBGS Optical Images of LIGs
Ishida, ApJL (2003)
Log LIR = 11.49 - 11.99
IRAS RBGS
Conclusion:
In the range log(Lir/Lo) = 11.6 - 12.0, LIGs are in the final stages of merging, with a typical “pre-merger” time of tm < 3 x 108 years
IRAS RBGS Optical Images
Log LIR = 12.00 - 12.51Ishida, ApJL (2003)
IRAS RBGS
Nuclear Separation vs. Lir
IRAS RBGS
Conclusion:
At log(Lir/Lo) > 12.0, > 40% of ULIGs have merged andthe remainder will merge within a time of tm < 108 years
SummaryProperties of IRAS RBGS+1Jy ULIG samples
Log(LIR/Lsun) = 11.40 - 12.70
• Sources are predominantly strongly interacting/merging spiral pairs MK Tot ~ 2 LK*• MK pair ratio < 3:1• LIR pair ratio < 5:1• Pairs are predominantly late type spirals (Sb, Sc)• Both components are molecular gas rich (MH2 ~ 109 - 10 Msun) pair separation as pair LIR
• ( Evidence for buildup of dense nuclear gas concentrations )
• ( Evidence for creation of luminous Seyfert 1 nuclei)
• ( Evidence for S + S E )
LCO
N=53
LHCN
LIR/LHCN
LIR/LCO
LHCN
LCO
Gao et al.Mirabel et al.Hibbard et al.Ponman et al.
Log (LIR/Lsun) = 11.01Int. Class = 3
UGC 83038 = Mrk 231Log (LIR/Lsun) = 12.57Int. Class = 4
Sanders et al.Hutchings & Neff
Scoville et al.Surace et al
SummaryNuclear Molecular Gas Concentrations @ r < 700 pc
General Results for ULIGs
• Mnuc/Mtot = 40 – 100 %
• Mnuc = 1 – 3 x 1010 Msun
(H2) ~ 0.65 – 2 x 1010 Msun
n (H2) spherical ~ 130 – 400 cm-3
• => ffnuc ~ 1 (for a population of W3-like GMCs)
N (H2) spherical ~ 10 23.2 – 23.7 cm-2
OVRO InterferometerBryant, Scoville et al. 1993-9
Summary
Optical Spectral Classification of LIGs+ULIGs
Veilleux, Kim & Sanders (1998) KPNO 4m + UH 2.2m
1-D surface brightness radial profiles
SummaryHost Properties of 1-Jy Sample of ULIGs
Log(LIR/Lsun) > 12.0
• redshift range: 0.018 – 0.271 MK Tot ~ 2.7 LK*
MR Tot ~ 2.5 LR*
• ~ 1/3 are E (r1/4-law profile @ r ~ 1.5 – 6.0 kpc)• ~ 1/3 are E/Sp• ~ 1/3 are “amorphous/chaotic”
Beyond the IRAS RBGS Sample …
Question:
What happens Next ?
A Plausible Scenario …
LIG ULIG QSO
Evolution of Fine Structure in a “post-merger” simulation Barnes (2002)
Evolution of the Luminosity Profile for a “Post-Merger” Remnant Barnes (2002)
R = 27.5 mag arcsec-2
(kpc)
Near-IR Imaging of PGQSOswith Gemini-North Hopuka’a AO System
(Olivier Guyon 2002)
PG 1411+442 40x40 kpc
“Raw Image” (resolution ~0.12 arcsec) PSF-subtracted image ~24 magH arcsec-2 (3)
NIR-AO Imaging of a Complete Sample of 38 PGQSOs Olivier Guyon, PhD Thesis, 2002
Raw (H-band) -psf - <radial profile>
Gemini-N 8m
NIR-AO Imaging of a Complete Sample of 38 PGQSOs Olivier Guyon, PhD Thesis, 2002
Raw (H-band) -psf - <radial profile>
Mean Radio-to-Xray SED of PGQSOs
Warped Disk Model Sanders, Phinney et al. (1989)
• PGQSOs typically have dominant spheroids + a moderate disk component (central bars, mini-spirals, …)
• PGQSO hosts typically have faint tidal debris
“SFR + MBH” versus Redshift
• Good evidence for S + S -> E merger sequence for ULIGs • Good evidence for creation of luminous Seyfert 1 nuclei in ULIGs• Confirmation of strong evolution with z in the ULIG population• ISOPHOT Deep Field sources consistent with LIG/ULIGs (z ≈ 0 -1.5)• ?? SCUBA Deep Field sources consistent with LIG/ULIGs (z ≈2 - 4)??
Summary
•[“SFR” vs. z ]opt+UV [“SFR” vs. z ]IRAS+ISO+SCUBA
•High-z ULIGs may represent epoch of spheroid / MBH formation