STUDIES SCUBA-2 Ultra Deep Imaging EAO Survey ang ( , ASIAA ) W - - PowerPoint PPT Presentation

STUDIES


SCUBA-2 Ultra Deep Imaging EAO Survey

W ei-Hao W ang (王 為豪, ASIAA)

• n behalf of the STUDIES Team

Outline

• Motivation
• Survey description
• Results from the first year
• 450 μm counts
• Counterpart properties
• case study: a z = 3.7 passive galaxy

• Half of the activities in the cosmic history is hidden by dust.
• 450 μm observations are sensitive to dust emission at

intermediate redshifts (z ~ 1-3)

Dole et al. (2006)

• 1

10

• 1

10

COB

23

10 101 102 103 104 105 Wavelength λ [ m] 10-10 10-9 10-8 10-7 10-6 W m -2 sr-1 106 105 104 103 102 101 Frequency ν [GHz] 10 101 102 103 104 105 Wavelength λ [μm] 10-10 10-9 10-8 10-7 10-6 W m -2 sr-1

CIB CMB

24 960 10-4 10-3 10-2 10-1 100 101 102 103 Wavelength (mm) 10-4 10-3 10-2 10-1 100 101 102 103 Flux (mJy) z=0.5 z=1 z=2 z=4 z=6 z=10

Redshifted Arp 220 SED

Motivation

Herschel 250 μm, 350 μm, 500 μm Ks, IRAC Ch1+2, IRAC ch3+4

SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES)

• An EAO JCMT Large Program
• To reach SCUBA-2 confusion limit at 450 μm (~10× deeper than

Herschel at 350/500 μm).

• 650 hr of observing time with Band-1 weather:

• STUDIES-COSMOS (330 hr, approved in 2015)

• STUDIES-SXDS (aka. UDS, 320 hr, approved in 2017)

• both in the CANDELS regions
• one Daisy pointing in each field


(D = 3’ ultradeep core + D = 15’ outer region)

• σ450μm ≲ 0.6 mJy in the core, < 3 mJy in the entire map
• execution period: 2015–2020
• about 130 team members

STUDIES: to detect typical dusty galaxies

850 μm confusion limit

STUDIES

• ptical samples

(extinction corrected)

850 μm samples

Herschel Limits

STUDIES

Barger et al. (2014)

• STUDIES will detect the typical members in the dusty galaxy population.
• STUDIES will probe into the SFR of optically selected galaxies.

STUDIES-COSMOS 


as of Feb 2017 (40% complete)

central rms ~ 0.9 mJy 98 sources at > 4 σ > 200 expected at full depth

SCUBA2 vs. Herschel

SCUBA-2 450 μm Herschel 500 μm

450 μm Counts


constrained with 4 σ sources and fluctuation analyses

Wang et al. (submitted, arXiv:1707.00990)

1 10 S450 (mJy) 100 102 104 106 dN/dS (deg-2 mJy-1)

Schechter Fit Power-Law Fit

LIR ~ 1.5×1011 L⨀, SFR ~ 25 M⨀/yr (z = 1.5)

4σ sources fluctuation analyses

1 10 10 S450

450 (mJy)

(mJy) 10 100 10 102 10 104 10 106 dN/dS (deg dN/dS (deg-2

• 2 mJy

mJy-1

• 1)

This Work, Schechter Fit This Work, Schechter Fit This Work, Power-Law Fi This Work, Power-Law Fit This Wor This Work Oliver (2010) Herschel 500 um Oliver (2010) Herschel 350 um Clements (2010) Herschel 500 um Clements (2010) Herschel 350 um Valiante (2016) Herschel 500 um Valiante (2016) Herschel 350 um

450 μm Counts


compared with Herschel SPIRE counts

Wang et al. (submitted, arXiv:1707.00990)

7x deeper

1 10 10 S450

450 (mJy)

(mJy) 10 100 10 102 10 104 10 106 dN/dS (deg dN/dS (deg-2

• 2 mJy

mJy-1

• 1)

This Work, Schechter Fit This Work, Schechter Fit This Work, Power-Law Fi This Work, Power-Law Fit This Wor This Work Oliver (2010) Herschel 500 um Oliver (2010) Herschel 350 um Clements (2010) Herschel 500 um Clements (2010) Herschel 350 um Bethermin (2012a) Herschel 500 um Bethermin (2012a) Herschel 350 um Glenn (2010) Herschel 500 um Glenn (2010) Herschel 350 um Valiante (2016) Herschel 500 um Valiante (2016) Herschel 350 um

300 300 400 400 500 500 600 600 λ ( (um) m) 0.0 0.0 0.2 0.2 0.4 0.4 0.6 0.6 0.8 0.8 1.0 1.0 Transmission Transmission

450 μm Counts


compared with Herschel SPIRE counts

Wang et al. (submitted, arXiv:1707.00990)

1 10 10 S450

450 (mJy)

(mJy) 10 100 10 102 10 104 10 106 dN/dS (deg dN/dS (deg-2

• 2 mJy

mJy-1

• 1)

This Work, Schechter Fit This Work, Schechter Fit This Work, Power-Law Fi This Work, Power-Law Fit This Wor This Work Oliver (2010) Herschel 500 um Oliver (2010) Herschel 350 um Clements (2010) Herschel 500 um Clements (2010) Herschel 350 um Bethermin (2012a) Herschel 500 um Bethermin (2012a) Herschel 350 um Glenn (2010) Herschel 500 um Glenn (2010) Herschel 350 um Valiante (2016) Herschel 500 um Valiante (2016) Herschel 350 um

300 300 400 400 500 500 600 600 λ ( (um) m) 0.0 0.0 0.2 0.2 0.4 0.4 0.6 0.6 0.8 0.8 1.0 1.0 Transmission Transmission

450 μm Counts


compared with Herschel SPIRE counts

Wang et al. (submitted, arXiv:1707.00990)

• Herschel 500 μm counts:

• 1.4× too high in flux

• r

• 2.5× too high in density
• Why?

• sources are clustered

• poor resolution (30″)


(Bethermin et al. 2007)

Resolved 450 μm Background

Wang et al. (submitted, arXiv:1707.00990)

1 10 S450 (mJy)

Bethermin (2012b) 450 µm model Lacey (2016) 450 µm model

Geach (2013) Casey (2013) Chen (2013b) Hsu (2016) Zavala (2017) This Work

10 100 Integrated Surface Brightness (Jy deg-2) 1 10 100 EBL Fraction (%)

Planck COBE

Counterpart Properties


(3GHz + 24 μm identification)

X.W. Shu et al. (in prep.)

450 μm detection limit (3.5 mJy, z=1) local galaxies

◇ ◇ PACS sources (Symeonidis 2013, z<1.5)

a case study

A High-z Quiescent Galaxy

• Glazebrook et al. (2017, Nature)
• ZF-COSMOS-20115:


a massive post-starburst quiescent galaxy at z=3.717.

• Quiescent because

• 1. strong Balmer absorption

• 2. no Herschel detection
• M★ = 1.7 × 10

11 M⊙

• requires a rapid formation

between z = 6 to 5.

Glazebrook et al. (2017)

Quiescent or Starburst?

• STUDIES detects it at 450

μm (3 σ) and 850 μm (10 σ). ALMA also detects it at 870 μm (7 σ).

• SFRobscured ~ 100 M⊙/yr.
• M★,unobscured ~ 0.8 × 1011 M⊙
• No longer requires a rapid

formation history at very high z.

Simpson et al. (2017)

Summary

• STUDIES will observe two fields with extremely high sensitivity

at 450 μm, from 2015 to 2020.

• Just 40% of the data in the COSMOS field (20% of whole

STUDIES) can produce a large sample and highly accurate counts.

• Herschel SPIRE counts are biased because of source clustering

and low resolution.

• non-detection in Herschel SPIRE bands ≠ quiescent.
• More SCUBA-2 data are coming. More studies and followup
• bservations are underway/planed.

Questions/Open Issues

• Nature of the offset between SCUBA2 and Herschel

counts:
 clustering?
 flux calibration?