The Cosmic Evolution of Neutral Atomic Hydrogen Gas

University of Sydney

Colloquium

27 November 2014

Philip Lah

Collaborators:

Frank Briggs (ANU)

Jayaram Chengalur (NCRA)

Matthew Colless (ANU)

Roberto De Propris (FINCA)

Michael Pracy (USyd)

Jonghwan Rhee (UWA)

Neutral Atomic Hydrogen Gas

in Galaxies

Galaxy M33: optical

Galaxy M33: HI 21-cm emission

Galaxy M33: optical and HI

Galaxy M33: optical

Why Study Neutral Atomic Hydrogen Gas?

HI Gas and Star Formation

neutral atomic hydrogen gas

cloud (HI)

molecular gas cloud (H

2)

star formation

The Cosmic Evolution

of Star Formation

The History of

Star Formation in the Universe

Why Study Neutral Atomic Hydrogen Gas?

Because you can measure it!

Why Study Neutral Atomic Hydrogen Gas?

Because you can measure it!

The Cosmic Evolutionof

HI Gas

Reionisation

HI density – nothing

How to measure?

1. HI 21-cm Emission

How to measure?

1. HI 21-cm Emission

Neutral atomic hydrogen creates 21 cm radiation

proton electron

Neutral atomic hydrogen creates 21 cm radiation

Neutral atomic hydrogen creates 21 cm radiation

Neutral atomic hydrogen creates 21 cm radiation

Neutral atomic hydrogen creates 21 cm radiation

photon

Neutral atomic hydrogen creates 21 cm radiation

Neutral atomic hydrogen creates 21 cm radiation

HI 21 cm emission decay half life ~10 million years

HI Mass

Assuming an optically thin neutral hydrogen cloud

1

2

1

236

kms

V

Mpc

d

mJy

S

zM

M LHI

MHI* = 6.2 ×109 M (Zwaan et al. 2003)

HI 21-cm Emission:

The Observations

HI density – HIPASS Zwaan05

HI density – HIPASS Zwaan05

Zwaan 2005 HIPASS 4315 galaxies

blind HI 21 cm emission direct

detection

HI density – ALFALFA Martin10

HI density – ALFALFA Martin10

Martin 2010ALFALFA 10,119 galaxies

blind HI 21 cm emission direct

detection

How to measure?

2. Damped Lyman-α Absorption

Systems

How to measure?

2. Damped Lyman-α Absorption

Systems

Lyman-α Absorption Systems

quasar

hydrogen gas clouds

Lyman-α emission

Lyman-α absorption by clouds

Wavelength

observer

Inte

nsi

ty

Damped Lyman-α

Lyman-α 1216 Å rest frame

Inte

nsi

ty

Wavelength (Å)4200 4400 4600 4800 5000 5200

Lyα emission

QSO 1425+6039 redshift z = 3.2 Keck HIRES optical spectrum

DLALyman-α forest

Damped Lyman-α: The Observations

HI density – Noterdaeme09

HI density – Noterdaeme09

Noterdaeme 2009 SDSS

937 absorbers

Damped Lyman-α

HI density – Noterdaeme12

HI density – Noterdaeme12

Noterdaeme 2012 BOSS

6839 absorbers

Damped Lyman-α

HI density – Zafar13

HI density – Zafar13

Zafar 2013 UVES

122 quasars

Damped Lyman-α

Lower Redshift Damped Lyman-α

HI density – Rao06

HI density – Rao06

Rao 2006 MgII–FeII

systems UV HST

197 systems

Damped Lyman-α

Coadding HI 21 cm Emission Signals

Coadding HI signals

RA

DEC

Radio Data Cube

Frequen

cy

HI red

shift

Coadding HI signals

RA

DEC

Radio Data Cube

Frequen

cy

HI red

shift

positions of optical galaxies

Coadding HI signals

frequency

flux

Coadding HI signals

frequency

flux

z2

z1

z3

z1, z2 & z3 optical redshifts

of galaxies

Coadding HI signals

velocity

z1

z2

z3

flux

velocity

Coadded HI signal

Coadding HI signals

velocity

z1

z2

z3

flux

velocity

Coadded HI signal

Noise m√ NN = number of galaxies

Coadding HI 21 cm Emission:

The Observations

HI density – Lah07

HI density – Lah07

Lah 2007GMRT/Subaru/AAT

154 galaxies

HI 21 cm emission stacking

HI density – Freudling11

HI density – Freudling11

Freudling 2011 AUDS Arecibo 18 galaxies

HI 21 cm emission targeted

HI density – Rhee13

HI density – Rhee13

Rhee 2013 WSRT CNOC 59 + 69 galaxies

HI 21 cm emission stacking

HI density – Delhaize13

HI density – Delhaize13

Delhaize 2013 Parkes 2dFGRS 3277 galaxies HIPASS 2dFGRS 15093 galaxies

HI 21 cm emission stacking

HI density – VVDS14

HI density – VVDS14HI 21 cm emission stacking

Rhee thesis VVDS14 GMRT/AAT/MMT 165 galaxies

HI density – zCOSMOS14

HI density – zCOSMOS14HI 21 cm emission stacking

Rhee thesis GMRT/zCOSMOS

HI density – Hoppmann14

HI density – Hoppmann14 HI 21 cm emission targeted

Hoppmann 2014 AUDS Arecibo 105 galaxies

HI density – Current StatusCurrent Status

HI density – Low z average

4σ

HI density – High z average

7σ

Neutral Atomic Hydrogen Gas

In Different Environments

Nearby Galaxy Clusters Are Deficient

In HI Gas

HI Deficiency in Clusters

DefHI =

log(MHI exp. / MHI

obs)

DefHI = 1

is 10% of expected

HI gas

Gavazzi et al. 2006

expected gas estimate based

on optical diameter and Hubble type

Cluster Stacking Observations

Abell 370, a galaxy cluster at z = 0.37

Abell 370 cluster core, ESO VLT image

large galaxy cluster of order same size

as Coma similar cluster

velocity dispersion and

X-ray gas temperature

cluster redshifts

AAT

Distribution of galaxies around Abell 370com

plete GM

RT

redshift range

Distribution of galaxies around Abell 370

cluster redshift

8 Mpc radius

region: 220

galaxies

Inner Cluster Region

Outer Cluster Region

HI density

Inner Cluster Region

Outer Cluster Region

HI density

cluster redshift

Distribution of galaxies around Abell 370

cluster redshift

Distribution of galaxies around Abell 370

within R200

region

110 galaxies

Inner Cluster Region

Outer Cluster Region

HI density

The Next Generation of Observations

Radio Telescopes

SKA1 SYSTEM BASELINE DESIGN 2013-03-12

Radio Telescopes

SKA1 SYSTEM BASELINE DESIGN 2013-03-12

Radio Telescopes

SKA1 SYSTEM BASELINE DESIGN 2013-03-12

Radio Telescopes

SKA1 SYSTEM BASELINE DESIGN 2013-03-12

Giant Metrewave Radio Telescope

• 45 m diameter dishes

• 30 dishes

• low frequency

HI density – GMRT

1000 MHz

~610 MHz

Karl G. Jansky Very Large Array

• 25 m diameter dishes

• 27 dishes

• high frequency

HI density –JVLA

1000 MHz

JVLA HI Survey

• CHILES (the COSMOS HI Large Extragalactic Survey) – z = 0 to 0.45, 1000 hours in B array

ASKAP

• 12 m diameter dishes

• 36 dishes

• focal plane array

HI density – ASKAP

700 MHz

ASKAP HI Surveys

• WALLABY (Widefield ASKAP L-Band Legacy All-Sky Blind Survey) - z = 0 to 0.26 - 75% of the entire sky- 9600 hrs

• DINGO (Deep Investigations of Neutral Gas Origins) - z = 0 to 0.4 - GAMA regions - 7500 hrs, ~290 deg2

• FLASH (The First Large Absorption Survey in HI) - a blind HI absorption-line survey, out to z = 1.0, 3000 deg2, 2400 hrs, HI stacking using WiggleZ redshifts

ASKAP HI Surveys

• WALLABY (Widefield ASKAP L-Band Legacy All-Sky Blind Survey) - z = 0 to 0.26 - 75% of the entire sky- 9600 hrs

• DINGO (Deep Investigations of Neutral Gas Origins) - z = 0 to 0.4 - GAMA regions - 7500 hrs, ~290 deg2

• FLASH (The First Large Absorption Survey in HI) - a blind HI absorption-line survey, out to z = 1.0, 3000 deg2, 2400 hrs, HI stacking using WiggleZ redshifts

ASKAP HI Surveys

• WALLABY (Widefield ASKAP L-Band Legacy All-Sky Blind Survey) - z = 0 to 0.26 - 75% of the entire sky- 9600 hrs

• DINGO (Deep Investigations of Neutral Gas Origins) - z = 0 to 0.4 - GAMA regions - 7500 hrs, ~290 deg2

• FLASH (The First Large Absorption Survey in HI) - a blind HI absorption-line survey, 0.5 < z <1.0, 25000 deg2, 3200 hrs, deeper pointings HI stacking using WiggleZ redshifts

MeerKAT

South African SKA pathfinder

• 13.5 m diameter dishes

• 64 dishes

HI density – MeerKAT

580 MHz

MeerKAT HI Surveys

• LADUMA – (Looking At the Distant Universe with the MeerKAT Array) – z > 1.0, ~5000 hours, single pointing Extended Chandra Deep Field South (ECDF-S)

The SKA-mid

The SKA-mid

• 64 × 13.5-m diameter dishes from the MeerKAT array and 190 × 15-m dishes

• ~15% of full SKA

HI density – SKA-mid

350 MHz

Then On To The

SKA

Additional Slides

A Radio Gravitational Arc?

Radio ArcV band optical

image from ANU 40 inch

Abell 370 cluster

8 arcmin square

Radio ArcV band optical

image from ANU 40 inch

Abell 370 cluster

8 arcmin square

Radio Arcoptical image from Hubble

Space Telescope

optical arc in Abell 370 was

the first detected gravitational

lensing event by a galaxy cluster (Soucail et al.

1987)

Radio Arc50 arcsec on a side

radio contour levels start at 28.5 μJy/ beam (3σ)

VLA L-band radio data has a synthesised beam size of

1.5 arcsec.∼

VLA C-band 4860 MHz

30 arcsec on a side

Peak 160 µJy/Beam

VLA L-band 1400 MHz

30 arcsec on a side

Peak 350 µJy/Beam

GMRT 1040 MHz

30 arcsec on a side

Peak 490 µJy/Beam

Theoretical Model of Arc

- based on Parametric Mass Model of Abell 370 by Richard et al. (2010)- images are 30.3 arcsec across, contour spacing geometric progression, with a factor 1.5 in between each contour

Radio Arc50 arcsec on a side

radio contour levels start at 28.5 μJy/ beam (3σ)

VLA L-band radio data has a synthesised beam size of

1.5 arcsec.∼

HI 21cm emission

• HI 21 cm emission decay half life ~10 million years

• 1 M 1.2 1057 atoms of hydrogen atoms

• total HI gas in galaxies ~ 107 to 1010 M

• HI 21 cm luminosity of ~2 1032 to 2 1035 ergs s-1

• in star forming galaxies luminosity of H emission ~3 1039 to 3 1042 ergs s-1

HI density –Molonglo??

Molonglo Bandwidth 3 MHz Centre frequency 843 MHz z = 0.681 to 0.687

Radio Arc Theory

Arc model based on Parametric Mass Model of Abell 370 published by Richard et al. (2010).images are 30.3 arcsec across, contour spacing geometric progression, with a factor 1.5 in between each contour

Giant Metrewave Radio Telescope