The Swift GRB Host Galaxy Legacy Surveydperley/talks/2014/rome/SHOALS.pdf · Daniel Perley The Swift Host Galaxy Legacy Survey Swift @ 10, Rome, Italy Daniel Perley (Caltech) + the

Swift @ 10, Rome, ItalyDaniel Perley The Swift Host Galaxy Legacy Survey

Daniel Perley (Caltech)+ the SHOALS collaboration:Antonio de Ugarte Postigo (IAA)Steve Schulze (PUC)Thomas Kruehler (ESO)Tanmoy Laskar (Harvard)Antonino Cucchiara (GSFC)Ranga Chary (Caltech)Jens Hjorth (DARK)Nial Tanvir (Leicester)Javier Gorosabel (IAA)Andrew Levan (Warwick)and many others

The Swift GRB Host The Swift GRB Host Galaxy Legacy SurveyGalaxy Legacy Survey

2014-11-12 2Swift @ 10, Rome, ItalyDaniel Perley The Swift Host Galaxy Legacy Survey

A large sample of GRB redshifts and host properties can constrain...

The History of Cosmic Star-Formation (out to very high redshift)

The Sites of Stellar Mass Assembly (including the faintest galaxies)

Connections between the ISM and Stellar Population(dust, metallicity, kinematics vs. mass, SFR, etc.)

The Nature of the GRB Progenitor(formation conditions; single star vs. binary-channel)

GRB Hosts as a Cosmological Tool


Selection criteria:• Occurred between 2005-2010• Swift detected; gamma-ray fluence > 10-6 erg/cm2

• Swift slewed immediately to the position• Far from the Sun at time of explosion (afterglow easily observable)• Low Milky Way foreground extinction• No nearby bright stars• Localized within 2”

(Similar procedure to VLT R/K-band host survey; Hjorth+2012)

→ 120 Swift GRBs (out of ~950 to date), 75% with predetermined redshift (usually from afterglow.)

(Currently 90% after host galaxy observations.) Redshift range 0.03 < z < 6.3

“SHOALS”:A large, deep, unbiased multiwavelength survey to include all host galaxies of all types at all redshifts.

The Swift Host Galaxy Legacy Survey


SHOALS Selection Criteria

Swift Host Galaxy Legacy Survey (PI Daniel Perley)

• Swift detected; gamma-ray fluence > 10-6 erg/cm2

• Swift slewed immediately to the position• Well-observed or at least well-observable:

(a) Autonomously triggered a 2m-class telescope, or(b) >5 hours from Sun and between 2005-2010, or(c) Satisfied TOUGH positional criteria

• Low Milky Way foreground extinction• No nearby bright foreground stars• Localized within 2”

Total w/redshift completeness All Swift bursts 855 303 35%

Jakobsson+2006 248 132 53% SHOALS 134 109 81%* TOUGH sample 69 58 84% BAT6 sample 58 53 91%

*before any additional host follow-up


The Swift Host Galaxy Legacy Survey

Spitzer (3.6 μm imaging): Good stellar mass proxy

(even with no color information); Sensitive to 101 0 M⊙ galaxies

to z~5 All targets observed to deep limits

(1-6 hours/target at z>1)

VLA (3 GHz continuum): Dust-unbiased SFRs 90 hours to observe 32 targets (from overlapping TOUGH survey)

Keck, Gemini, VLT, GTC Optical/NIR imaging for full SED modeling (age, extinction, improved stellar masses) Spectroscopy to complete redshift distribution Numerous programs ongoing


Spitzer (3.6 μm imaging): Good stellar mass proxy

(even with no color information); Sensitive to 101 0 M⊙ galaxies

to z~5 230-hour large program to observe all SHOALS targets

(+ some others of interest) PI D. Perley

Keck, Gemini, VLT, GTC Spectroscopy to complete redshift

distribution, measure metallicities of some galaxies

Multicolor optical/NIR imaging for full SED modeling

(age, extinction, improved stellar masses) Ongoing, worldwide campaign


130 GRB Host Galaxies from Spitzer


130 GRB Host Galaxies from Spitzer


GRB host NIR luminosities to z~6

(unknown redshift)Redshift

Rest-frame Wavelength (μm)

Abs

olut

e m

agn i

tude

(A

B)


GRB host stellar masses to z~6



108 Mo

101099 M Moo

10101 01 0 M Moo

10101 11 1 M Moo

Abs

olut

e m

agn i

tude

(A

B)

stel

lar

ma

ss →





Abs

olut

e m

agn i

tude

(A

B)

Milky Way

LMC

SMC108 Mo

101099 M Moo

10101 01 0 M Moo

10101 11 1 M Moo

stel

lar

ma

ss →




Abs

olut

e m

agn i

tude

(A

B)


Milky Way

LMC

SMC




Abs

olut

e m

agn i

tude

(A

B)


100% complete above m<23.2

Milky Way

LMC

SMC




Abs

olut

e m

agn i

tude

(A

B)


97% complete above m<24.4

Milky Way

LMC

SMC




Abs

olut

e m

agn i

tude

(A

B)


Milky Way

LMC

SMC

90% complete to full survey depth90% complete to full survey depth70% of targets are detected70% of targets are detected;;all but a few nondetections have strict upper limitsall but a few nondetections have strict upper limits




Abs

olut

e m

agn i

tude

(A

B)


Milky Way

LMC

SMC


GRB host redshift evolution


Abs

olut

e m

agn i

tude

(A

B)


Milky Way

LMC

SMC

Median GRB host mass ~7x10Median GRB host mass ~7x1099 at z=1-4 at z=1-4

… … but less than 10but less than 1099 at z<0.5! at z<0.5!

“cosmic downsizing”, but on steroids – to be continued...


GRB host redshift evolution

z = 0 - 0.5z = 0.5-1.0 z = 1.0-1.5 z = 1.5-2.0z = 2.0-2.5 z = 2.5-3.5 z = 3.5-5.0 z > 5.0

(includes upper limits)

Absolute magnitude (AB) at λ = 3.6/(1+z)-16 -17 -18 -19 -20 -21 -22 -23 -24

107 108 109 1010 1011Stellar mass (M⊙)


GRB hosts vs. SFR-selected galaxies



median mass for GRB hostsmedian mass for GRB hosts

Milky Way

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)





Grey points:GOODS-N galaxies from Kajisawa+2011


Milky Way

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)





Grey points:GOODS-N galaxies from Kajisawa+2011

median SFR-weighted mass for galaxiesmedian SFR-weighted mass for galaxies


Milky Way

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)





field survey completeness limit


median SFR-weighted mass for galaxiesmedian SFR-weighted mass for galaxiesMilky Way

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)







median mass for median mass for m<24.25 hostsm<24.25 hosts

median SFR-weighted mass for median SFR-weighted mass for m<24.25 galaxiesm<24.25 galaxies

MW

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)







LMC

SMC

MW

Median Median luminosities luminosities consistent at z>2consistent at z>2

Abs

olut

e m

agn i

tude

(A

B)







Galaxy cosmic Galaxy cosmic downsizingdownsizing

GRB cosmic GRB cosmic downsizingdownsizing

LMC

SMC

MW

Abs

olut

e m

agn i

tude

(A

B)







GRBs almost totally absent in M > 101 0 galaxies since z~1

(… but not at z~2 or z~3)

MW

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)


Luminosity Distribution vs. Galaxies

z < 0.5z < 0.5

z > 5.0

z = 0.5-1.0 z = 1.0-1.5 z = 1.5-2.0

z = 2.0-2.5 z = 2.5-3.5 z = 3.5-5.0

107 108 109 1010 1011 107 108 109 1010 1011 107 108 109 1010 1011 107 108 109 1010 1011

-16 -18 -20 -22 -24 -18 -20 -22 -24 -18 -20 -22 -24 -18 -20 -22 -24

SFR

-wei

ghte

d ga

laxi

es

GR

B h

osts


Luminosity Distribution vs. Galaxies

z < 0.5z < 0.5

z > 5.0

z = 0.5-1.0 z = 1.0-1.5 z = 1.5-2.0

z = 2.0-2.5 z = 2.5-3.5 z = 3.5-5.0

107 108 109 1010 1011 107 108 109 1010 1011 107 108 109 1010 1011 107 108 109 1010 1011

-16 -18 -20 -22 -24 -18 -20 -22 -24 -18 -20 -22 -24 -18 -20 -22 -24

GR

B h

osts

1010 4x1010 1011

SFR

-wei

ghte

d ga

laxi

es

(lum

inos

ity c

utof

f)


Sharp Metallicity Cutoff?

z~0.1

z~0.3

z~0.8

z~1.6

Zahid et al. 2014z~1.2(interpolated)

KK04scale

z~2

z~3

Kewley et al. 2008 Erb et al. 2006Maiolino et al. 2008,2009



z~0.8z~1.6

7 8 9 10 11

1.0-1.5

1.5-2.0Zahid et al. 2014

z~1.2(interpolated)

KK04scale

0.5-1.0 0.5-1.0

1010

4x10101011



z~0.8z~1.6

7 8 9 10 11

1.0-1.5

1.5-2.0Zahid et al. 2014

z~1.2(interpolated)

KK04scale

0.5-1.0 0.5-1.0

1010

4x10101011



z~0.1

z~0.3

z~0.8

z~1.6

7 8 9 10 11

1.0-1.5

1.5-2.0Zahid et al. 2014

z~1.2(interpolated)

KK04scale

0.5-1.0 0.5-1.0

1010

4x10101011

z~2

z~3

Kewley et al. 2008 Erb et al. 2006Maiolino et al. 2008,2009






MW

LMC

SMC

Abs

olut

e m

agn i

tude

(A

B)






MW

LMC

SMC

Stifled due to metal buildup in massive galaxies

Abs

olut

e m

agn i

tude

(A

B)

galaxies dominate cosmic SFR at every epoch from 1 < z < 6But probably not at z>6; Tanvir et al. 2012

~109 - 101 1 M ⊙


Stellar mass and dust obscuration


Abs

olut

e m

agn i

tude

(A

B)


MW

LMC

SMC




Abs

olut

e m

agn i

tude

(A

B)


red: dark or dusty bursts

MW

LMC

SMC




Abs

olut

e m

agn i

tude

(A

B)


Low-mass Low-mass galaxies are galaxies are rarely dustyrarely dusty

13/18 heavily 13/18 heavily obscuredobscured

3/32 heavily 3/32 heavily obscuredobscured

High-mass High-mass galaxies are galaxies are usually usually dustydusty

MW

LMC

SMC


ConclusionsGRBs probe typical star-forming galaxies at high redshift (z>1.5)

Median host mass is ~6×109 M☉, intermediate between LMC and MW.Host mass distribution agrees with SFR-weighted galaxy population; weak dependence on environment at these redshifts.Very little evolution in host mass distribution between 1.5 < z < 5.

No large, unseen population of low-mass galaxies.Deep mass-selected surveys see most cosmic SFR out to z~6.

GRB host properties significantly diverge from cosmic SFR at z<1They strongly avoid high-mass galaxies (“cosmic downsizing on steroids”)Suggests strong suppression above ~0.5-1.0 Z☉.

Possible additional dependencies (sSFR?)

GRBs provide novel constraints on high-z dust.Low-mass galaxies contain very little dust and are optically thin;

high-mass galaxies have lots of dust with high covering fraction.No strong connection between dust and galaxy properties

outside Local Group.GRBs support a significant (but non-dominant) contribution to

cosmic SFR from ULIRGs at z>1.



Dust and Selection Bias

Av ~ 1 magunderrepresented

Av ~ 5 magmissing completely

(Compiled from data in Kann et al. 2003 & 2010, Cenko et al. 2009, Perley et al. 2009, Greiner et al. 2011)

~20% of GRBs are systematically missing from optical afterglow searches as a result of dust.

See if adding enough of these events makes a difference!

Observed Av Observed Av distributiondistribution(optically bright events)(optically bright events)


Different Host MorphologiesGRBs SNe


Lower Host Metallicities

Graham & Fruchter 2013(Levesque+2010, Modjaz+2008) Luminosity →

Met

alli

city

→

Core-collapse supernova hosts (z<0.5):Core-collapse supernova hosts (z<0.5):Type IIType IIType Ic/blType Ic/blGRB hosts


Lower Host Metallicities

Graham & Fruchter 2013(Levesque+2010, Modjaz+2008) Luminosity →

Met

alli

city

→

Core-collapse supernova hosts (z<0.5):Core-collapse supernova hosts (z<0.5):Type IIType IIType Ic/blType Ic/blGRB hosts

~0.7 Z☉

GRBs “common”(~1 per 105 SN)

GRBsrare

(~1 per 106 SN)

Documents

The Swift GRB Host Galaxy Legacy Surveydperley/talks/2014/rome/SHOALS.pdf · Daniel Perley The Swift Host Galaxy Legacy Survey Swift @ 10, Rome, Italy Daniel Perley (Caltech) + the