Star formation and submm/far-Star formation and submm/far-IR luminous galaxiesIR luminous galaxies

Andrew Blain Andrew Blain

CaltechCaltech

2626thth May 2005 May 2005

Kyoto COSMOS meeting

Resolved `example’: the AntennaeResolved `example’: the Antennae

Excellent example of distinct Excellent example of distinct opt/UV and IR luminosityopt/UV and IR luminosity– BUT modest luminosityBUT modest luminosity

Interaction long known, Interaction long known, but great luminosity but great luminosity unexpected unexpected – ~90% energy escapes ~90% energy escapes

at far-IR wavelengths at far-IR wavelengths

Resolved images Resolved images important important – Relevant scales Relevant scales

~1” at high ~1” at high redshiftredshift

HST WFPC2

ISOCAM

CSO/SHARC-2Dowell et al.

Current status and questionsCurrent status and questionsThe most luminous high-z galaxies emit most radiation in far-IRThe most luminous high-z galaxies emit most radiation in far-IRAssociated with forming ellipticals/bulges? Arguments: space density, Associated with forming ellipticals/bulges? Arguments: space density, dynamical CO mass, clusteringdynamical CO mass, clustering– All will be better established by COSMOSAll will be better established by COSMOS– Need to find these things ‘ULIRGs’ - few 10Need to find these things ‘ULIRGs’ - few 101212LLoo

MAMBO (Eva Schinnerer & MPI/Bonn) and BOLOCAM (James Aguirre, MAMBO (Eva Schinnerer & MPI/Bonn) and BOLOCAM (James Aguirre, U Colorado / CSO Caltech)U Colorado / CSO Caltech)– MAMBO 1.25mm, 1mJy RMS over 0.13 degMAMBO 1.25mm, 1mJy RMS over 0.13 deg22

– BOLOCAM 1.1mm, 2.5 mJy RMS over 0.28 degBOLOCAM 1.1mm, 2.5 mJy RMS over 0.28 deg22

– I.e. BOLOCAM 3x coarser resolution, 3x higher noise, 2x wider areaI.e. BOLOCAM 3x coarser resolution, 3x higher noise, 2x wider area– BOLOCAM noise very uniform: can probe fluctuations from faint sources, at BOLOCAM noise very uniform: can probe fluctuations from faint sources, at

1-1- level level

Reasonable coverage over 15% of HST COSMOSReasonable coverage over 15% of HST COSMOS– Future APEX/SCUBA-2 survey for whole regionFuture APEX/SCUBA-2 survey for whole region

Knowledge of properties of far-IR/submm galaxies properties link to Knowledge of properties of far-IR/submm galaxies properties link to SpitzerSpitzer strategies - in addition to BzK selection strategies - in addition to BzK selection

Multiwavelength detailsMultiwavelength details

Radio (RMS~10Radio (RMS~10Jy) is just adequate to reach the Jy) is just adequate to reach the most luminous galaxies over z~1-2most luminous galaxies over z~1-2Ground-based photometry will help with a real test of Ground-based photometry will help with a real test of viability of photo-z’s for these objects - how red and viability of photo-z’s for these objects - how red and recognizable?recognizable?X-ray data over uniquely large field will identify the X-ray data over uniquely large field will identify the minority of powerful AGN in the sampleminority of powerful AGN in the sample– can use limits from Spitzer/submm to better assess can use limits from Spitzer/submm to better assess

opacity in AGN opacity in AGN

Can they be identified with red objects?Can they be identified with red objects?– WFC3 WFC3 – IF HST is serviced COSMOS may be key beneficiary IF HST is serviced COSMOS may be key beneficiary

Spitzer colors/fluxesSpitzer colors/fluxesSpitzer rest near-IR Spitzer rest near-IR and mid-IR red and mid-IR red sources can be sources can be ID’ed as submm ID’ed as submm galaxies with galaxies with reasonable reasonable efficiency efficiency 8/4.5 > 1, 24/8 >3 is 8/4.5 > 1, 24/8 >3 is reasonable cutreasonable cut– Met by COSMOS Met by COSMOS

observationsobservations

Should provide Should provide decent sample of decent sample of high-z ULIRGS for high-z ULIRGS for LSSLSS

8m / 4.5m

24m

/ 8

m

Big symbols are submm galaxies (SMGs): size scales with zSmall symbols Lockman Hole & GOODS-N Spitzer galaxies

Appropriate Appropriate SpitzerSpitzer depths depths24/824/8m vs 24m vs 24mm

Large: SMGsLarge: SMGs

Small: IRACSmall: IRAC

Lockman & Lockman & GOODS-NGOODS-N

Most existing Most existing examples found if examples found if sensitivity is to sensitivity is to 100100Jy at 24Jy at 24mm

Need to go ~30 Need to go ~30 times deeper at 8times deeper at 8mm

2424m fluxm flux

2424

m/8

m/8

m c

olor

m c

olor

SummarySummaryCOSMOS contains largest mm-wave imagesCOSMOS contains largest mm-wave images– Still at relatively early stageStill at relatively early stage

Much better multiwavelength coverage than other Much better multiwavelength coverage than other fieldsfields– AGN - starburst discriminationAGN - starburst discriminationSpitzer data will assist dramatically Spitzer data will assist dramatically – If deep enough to exploit to identify mid-IR bright If deep enough to exploit to identify mid-IR bright

galaxies in color-color spacegalaxies in color-color spaceLimits on far-IR properties of the zoo of interesting Limits on far-IR properties of the zoo of interesting lower-z objects are valuablelower-z objects are valuablePathfinder for future instruments: APEX, SCUBA-2 & Pathfinder for future instruments: APEX, SCUBA-2 & ultimately ALMAultimately ALMA