A Larger, Deeper Survey of Submillimeter Galaxies Attila Kovcs - - PowerPoint PPT Presentation

▶
a larger deeper survey of submillimeter galaxies
SMART_READER_LITE
LIVE PREVIEW

A Larger, Deeper Survey of Submillimeter Galaxies Attila Kovcs - - PowerPoint PPT Presentation

Sep 01, 2023 333 likes •887 views

A Larger, Deeper Survey of Submillimeter Galaxies Attila Kovcs University of Minnesota Axel Weiss MPIfR I. Smail, K. Coppin, F. Walter, T. Greve et al. 2009 University of Minnesota Arp 220 The Energy Spectrum of a Luminous Galaxy Source:

slide-1
SLIDE 1

A Larger, Deeper Survey of Submillimeter Galaxies

Attila Kovács

Axel Weiss

  • I. Smail, K. Coppin, F. Walter, T. Greve

et al. University of Minnesota MPIfR 2009 University of Minnesota

slide-2
SLIDE 2

Arp 220

Source: NED

The Energy Spectrum of a Luminous Galaxy

slide-3
SLIDE 3

35 K (dust)

Arp 220

The Energy Spectrum of a Luminous Galaxy Milky Way FIR fraction is about 50%, T~16K

slide-4
SLIDE 4

Arp 220 at z=2.3

The Energy Spectrum of a Distant Luminous Galaxy? FIR is also good for studying distant populations?

slide-5
SLIDE 5

The Cosmic Background

Hasinger 2000

Infrared (and optical?) background may be due to such galaxies....

slide-6
SLIDE 6
  • T. Greve

K-Correction Benefits...

850 micron is equally sensitive to the same galaxy at z ~ 1-8...

slide-7
SLIDE 7

Atmospheric Transmission at APEX

Sky is Bright

Analogy: Imaging a 17 mag star on a bright summer day

slide-8
SLIDE 8

A Galaxy far far away... (10 Gly, 35K) atmosphere (300K)

Bolometers

Bolometers are just thermometers doing the impossible...

slide-9
SLIDE 9

1998

slide-10
SLIDE 10

Submillimeter Galaxies (SMGs) Hughes et al. 1998

Hughes et al. 1998

The First Detections

SCUBA

Too many optical counterparts Or none at al...

slide-11
SLIDE 11

1998

Hughes et al. 1998

2003 2003

slide-12
SLIDE 12

Redshift Distribution of SMGs Chapman et al 2003, 2005

Chapman et al. (2005)

Hopkins 2006

z ~ 2.3

Optical redshifts At the radio ID position

slide-13
SLIDE 13

2 6 0.5 3 1 2 z 1000

SMGs (z~1-3)

slide-14
SLIDE 14

1998 2003 2003

Hughes et al. 1998 Chapman et al. 2003 & 2005

2006

slide-15
SLIDE 15

Temperatures & Luminosities Radio-FIR Correlation

Kovács et al. 2006

T ~ 35K, L ~ 1013 Lsun Luminosities fueled by star-formation

slide-16
SLIDE 16

SHADES Coppin et al 2006

SCUBA Lockman Hole (485 arcmin2) SXDF (406 arcmin2) SCUBA Half Degree Squared survey 37 pixels

slide-17
SLIDE 17

SHADES: Source Counts (brightness distribution)

Coppin et al. 2006

Stellar Analogy: IMF Formation Evolution (z-Distribution)

slide-18
SLIDE 18

1998 2003 2006 2003 2007

Hughes et al. 1998 Chapman et al. 2003 & 2005 Coppin et al. 2006

SHADES

Kovács et al. 2006

slide-19
SLIDE 19
slide-20
SLIDE 20

LABOCA

(Large Bolometer Camera)

Siringo et al. 2009

295 pixels

slide-21
SLIDE 21
slide-22
SLIDE 22

X-ray Chandra, XMM UV GALEX Opt HST GEMS/GOODS, COMBO-17 IR Spitzer IRAC/MIPS Radio VLA 1.4GHz

30'

CHANDRA Optical

The Extended Chandra Deep Field South (CDFS)

slide-23
SLIDE 23

mJy/beam

300 hours 19” beam (27” smoothed) 1.2 mJy/beam 125 sources (5 false)

The CDFS at 870 microns

slide-24
SLIDE 24

mJy/beam

The CDFS at 870 microns

300 hours 19” beam 1.2 mJy/beam 125 sources (5 false)

slide-25
SLIDE 25

30'

slide-26
SLIDE 26

Confusion Noise

Rule of Thumb When the number

  • f sources per

beam exceeds 1, sources start to look like a noisy background.... σc ~ 0.7 mJy/beam Observed noise is the combination of measurement noise and confusion noise σ2

  • bs = σ2

m + σ2 c

slide-27
SLIDE 27

SHADES Recipe

  • 1. Bin your sources
  • 2. Assume dN/dS
  • 3. Deboost with
  • 4. get dN/dS

How to Get Source Counts...

The “Direct” Method...

slide-28
SLIDE 28

P(D) Analysis

Many faint sources Widen distribution (confusion) Bright sources Produce tail

P(D) analysis

Observed distribution is a product of the source distribution and the underlying noise...

slide-29
SLIDE 29

Schechter Barger

slide-30
SLIDE 30

P(D) Results

Power Law Smin = 0.5 mJy N0 = 92.7 mJy-1 deg-2 p = 3.178

slide-31
SLIDE 31

Source Counts from the CDFS

Integrated 870um Background: 29-33 Jy/deg2 COBE: 45 +- 5 CDFS SHADES

slide-32
SLIDE 32

The Perfect View

Over 12,000 sources mJy/beam

slide-33
SLIDE 33

Cosmic Variance?

Z > 2 K-band selected galaxies are under-abundant by ~60%. (Dokkum et al. 2006) Z > 2.5 DRGs (Marchesini et al. 2006) High-z optically bright AGNs (Dwelly & Page 2006)

Underdensities In the CDFS:

slide-34
SLIDE 34

mJy/beam

Spatial Source (Flux) Distribution

slide-35
SLIDE 35

Bright Source Flux Distribution

Smoothed to 5' resolution

slide-36
SLIDE 36

Cosmic Variance?

Sparse Dense

22-28 Jy/deg2 30-38 Jy/deg2

slide-37
SLIDE 37

Cosmic Variance?

Seems more a variation in steepness rather than density

slide-38
SLIDE 38

(assumed) Clustering of SMGs consistent with other high-z populations Corresponds to present epoch galaxy clusters Associated with more massive DM halos

The Perfect View

slide-39
SLIDE 39

Greve et al. 2009

Other high-z Populations

slide-40
SLIDE 40

Largest, deepest, cleanest to date 125 Galaxies A Better way of Analyzing Data Robust Source Counts Cosmic Variance?

Summary (so far...)

slide-41
SLIDE 41

Need Redshifts...

PHOTOMETRIC SPECTROSCOPIC

e.g. from Spitzer IRAC/MIPS Problem: Ambiguous MIR Ids Within search radius Based on radio Positions From VLA 1.4 GHz Problem: Deep radio surveys have Known redshift cutoff at z~3 NEED BETTER POSITIONS For securing ID NEED BETTER POSITIONS For optical followup

slide-42
SLIDE 42

Pope et al. 2006 3.6um 24um ACS VLA

Troublesome IDs

slide-43
SLIDE 43

My Big Question...

(What about the other half of SMGs?) FIR emission is not fueled by star-formation... AGNs? More SMGs at z>3 than we think

slide-44
SLIDE 44

Looking for New Ways...

Combined MIR/NIR analysis for isolating potential candidates (Wilson et al. 2004) E-VLA followup positions from thermal continuum, possibly redshift from CO(1-0) Wide band submm grating spectrometers For CO or CI transitions (e.g. z-SPEC) Herschel (esp. 200um) ALMA...

slide-45
SLIDE 45

Interested?

slide-46
SLIDE 46

Completeness

Astrometry

slide-47
SLIDE 47

LABOCA Beam Shape

slide-48
SLIDE 48

BzK Selection

slide-49
SLIDE 49
slide-50
SLIDE 50

Measured a Flux Sobs with some uncertainty What was the underlying flux producing the signal?

slide-51
SLIDE 51

Measured a Flux Sobs with some uncertainty What was the underlying flux producing the signal? A B Meaning: Probability of measuring value of Sobs, if the true value is S

slide-52
SLIDE 52
slide-53
SLIDE 53

When the underlying flux distribution p(S) is skewed....

E(S) = Sobs Deboosting

slide-54
SLIDE 54

A More pathological Case of deboosting...

p(S) ~ S-p