Understanding the Physics of the Bulge/Black-Hole Connection

with GSMT

Stephen EikenberryUniversity of Florida

3 November 2007

Black Holes – Why Care?• Black holes are

fundamental influences on many astrophysical phenomena

• Super-massive BH’s now known to be intrinsically linked to galaxy evolution

• But how/why?? What is the physics of the Bulge/Black-Hole (BBH) connection?

• Probably related to nuclear gas flow …

Ferrarese et al., 2001

The Galactic Center• The Galactic Center is a wonderful & mysterious place:

• >4.5x106 M0 black hole in Sgr A*• Closest galaxy on BBH correlation curve• (Also >2000 Chandra X-ray sources -- the “Elephant’s

Graveyard” for (stellar mass) black hole hunters!!)

GC Surveys: The Problem• ~100% of all Chandra

X-ray sources have IR counterpart candidates within 1-arcsec

• But, stats indicate that ~85% are SPURIOUS

• Need to sort the wheat from the chaff!

• IR spectra do it (but need N=2000, and most are “throw-aways”! TAC issue!!)

FLAMINGOS-2 GC Survey• F2GCS Team: S. Eikenberry, R. Bandyopadhyay, C. DeWitt,

N. Raines (Florida); R. Blum & K. Olsen (NOAO); K. Sellgren (OSU); M. Muno (Caltech); etc.

FLAMINGOS-2 Summary:

•Gemini 8-m NIR imager/MOS

•1-2.5-micron, HAWAII-2

•6.2-arcmin-diam. imaging FOV

•6x2-arcmin MOS FOV; N>60 targets

•R~1300 JH, HK; R~3300 J,H,K

•MCAO-compatible

FLAMINGOS-2 GC Survey• F2GCS will obtain HK spectra of ~5000 stars in GC

region (w/ISPI pre-imaging for target selection)• Will target ~2000 X-ray sources to identify ~300 new

X-ray binary IR counterparts (doubling the number currently known in the Galaxy; >x100 sample in the GC region)

• Should resolve the mystery of this new source population

• What about the other stars? (5000 – 300 = 4700 “throw-aways”)

FLAMINGOS-2 GC Survey:RGB Heaven

• One person’s “chaff” is another person’s “wheat”!

• Produces a catalog of ~4000-ish RGB spectra hurray! (?)

• Use H&K steam bands and CO indices Mbol & Teff

• Now we can place 4000 RGB stars on an H-R diagram hurray! (?)

Blum et al., 2003

F2GCS: Star Formation History

• Combine with model star formation histories we can constrain the SFH of the GC

• SFH traces nuclear gas flow versus time (hurray!)• Can link this to the mass evolution history of the SMBH!!

Blum

, Ram

irez, Sellgren,

Olsen 2003

•F2GCS increases sample x60 !

•F2GCS reaches much fainter too

The Bulge/Black-Hole Connection• Follow-up on F2GCS

(Gen 1 & 2) + other inner surveys with:– FRIDA on GTC– Keck NGAO & IR d-

IFU (?)• HK + R=20,000 will

provide abundances (, Fe) & kinematics

• Then know history of nuclear gas flow (mass, kinematics, & composition versus time) !

• physics of the Bulge/Black-Hole connection (!)

Smith et al., 2002

Black Hole Origins: Beyond the Milky Way• F2GCS will probe the

origins of Sgr A* by studying the properties/history of the stellar population around it

• Future programs will study the origins of black holes in external galaxies with same resolved approach

• GSMT can resolve individual RSG stars in Virgo Cluster galaxies!

Virgo Cluster Black Holes & Bulges• GSMT + AO + IR

integral field unit gives MBH (CaII triplet)

• Offset IFU (multi-pointings or multi-dIFU) gives bulge

• With GSMT spatial res, get individual red supergiant stars• H ~20-23 mag• K ~19-22 mag

• GSMT S/N OK!

Note: GSMT with IRIS/IRMOS-like instruments can achieve much greater bandpass than this!

Virgo: What About Crowding?• Un/partly-resolved stellar

background important• IFU analysis approaches:

• spectra of many spatial points

• photometry w/many spectral channels

• Adopt Olsen et al. approach to ELT crowding

• Conclusion crowding is non-trivial, but also non-crippling for this science

Virgo Cluster Survey• Use AO-fed IR IFU with multiple pointings (or AO-fed

multi-dIFU with single pointing) on an individual Virgo cluster galaxy

• Results:• MBH ; bulge

• Nuclear gas flow history (incl. abundance + kinematics!) from stars/SFH

Physics of BBH Connection (like Sgr A*)• Repeat for many Virgo galaxies probe how the physics

of BBH changes with galaxy properties/environment• The Virgo Cluster becomes a natural test laboratory for

the Bulge/Black-Hole Connection !!

GSMT Instrument Requirements• Near-Diffraction-limited AO in

H/K bands• IR IFU with R~5K-7K and

R~20K:• Need high-res grating, but

still 1st order and “normal” grating constant (i.e. FRIDA)

• Need multiple pointings• Or IR multi-dIFU with R~5K-

7K and R~20K: i.e. UF IRMOS concept• High-res grating incl. in

baseline design• Multi d-IFUs can get entire

galaxy in one go!

Conclusions• BBH investigations using resolved stellar studies can tie

Black Hole evolution to feeder gas via Star Formation History (incl. abundance, kinematics)

• 8-m-class telescopes will do this for the Milky Way + M33 (i.e. Gemini/FLAMINGOS-2 Galactic Center Survey)

• GSMT (ELTs) + right instruments can do this same work out to the Virgo Cluster supermassive black hole astrophysics test laboratory

• Cost: Need AO-fed IR IFU (or multi-dIFU) grating/filter slots to include 2 “high-res” 1st-order gratings (in other words, CHEAP incremental cost compared to existing instrument plans for many/most ELTs!)