Probing galaxy assembly and Probing galaxy assembly and evolution through neutral evolution through neutral hydrogen studieshydrogen studies

Patricia (Trish) HenningPatricia (Trish) Henning

University of New MexicoUniversity of New Mexico

2010 SKA SA Project Postgraduate Bursary 2010 SKA SA Project Postgraduate Bursary ConferenceConference

Stellenbosch, 2 December 2010Stellenbosch, 2 December 2010

Galaxy formation, Galaxy formation, evolutionevolution A major unsolved problem in A major unsolved problem in

astrophysics: how does a galaxy astrophysics: how does a galaxy accrete baryons, and subsequently accrete baryons, and subsequently form stars?form stars?– Simulations unable to Simulations unable to

comprehensively represent gas comprehensively represent gas physics, reproduce galaxiesphysics, reproduce galaxies

– Observations just beginning to detect Observations just beginning to detect star formation fuel over range of star formation fuel over range of redshifts and environmentsredshifts and environments

Major and minor mergers?Major and minor mergers? Smooth accretion from IGM?Smooth accretion from IGM?

– ““Hot mode” Shock-heat, form diffuse Hot mode” Shock-heat, form diffuse hot halo componenthot halo component

– ““Cold mode” Cold, filamentary Cold mode” Cold, filamentary accretionaccretion

– What happens when, where, to which What happens when, where, to which galaxies?galaxies?

Fig from D. Fig from D. KeresKeres

HI observations reveal HI observations reveal evidence of ongoing evidence of ongoing interactions/accretion interactions/accretion of cold gasof cold gas

Extraplanar gas: disk-Extraplanar gas: disk-halo flow, also cold halo flow, also cold accretion?accretion?

Sancisi et al. 2008Sancisi et al. 2008

HI traces “environmental HI traces “environmental impact” impact” How do galaxies

gain and lose gas? Infall vs. removal processes

Gas serves as a tracer of interactions

Chung et al.Chung et al.

Bauermeister & BlitzBauermeister & Blitz

220 kpc

NGC 4254 AreciboNGC 4254 Arecibo

What we need to knowWhat we need to know• the evolution of the HI content of the evolution of the HI content of

galaxies from z~2 to z=0galaxies from z~2 to z=0• the accretion of gas onto galaxiesthe accretion of gas onto galaxies• the complete census of HI the complete census of HI

clouds/emission in the halos of galaxies clouds/emission in the halos of galaxies arising from the condensation of hot gasarising from the condensation of hot gas

• the effect of environment the effect of environment • fine scale structure of the ISM in star-fine scale structure of the ISM in star-

forming galaxiesforming galaxies

• HI surveys are far behind our HI surveys are far behind our O/IR colleagues in size, depth, O/IR colleagues in size, depth, resolutionresolution

HI surveys – the pastHI surveys – the past

HI Parkes All Sky Survey - HIPASS HI Parkes All Sky Survey - HIPASS (2004; Meyer, Zwaan et al.)(2004; Meyer, Zwaan et al.)

– All southern hemisphere, plus northern All southern hemisphere, plus northern extension to Dec = +25 degextension to Dec = +25 deg

– 5300 galaxies over 70% of sky5300 galaxies over 70% of sky– sensitivity 13 mJy per 15 arcmin beam, sensitivity 13 mJy per 15 arcmin beam,

at 18 km/s velocity resolutionat 18 km/s velocity resolution– 64 MHz BW, -1280 – 12,700 km/s64 MHz BW, -1280 – 12,700 km/s

– 280 galaxies with log M280 galaxies with log MHIHI < 8.5 in south < 8.5 in south

HIMF for 4315 southern HIPASS sources HIMF for 4315 southern HIPASS sources Omega(HI), using HI emission, 3.5 x 10Omega(HI), using HI emission, 3.5 x 10-4-4

Meyer et al. 2004Meyer et al. 2004

Zwaan et al. 2005Zwaan et al. 2005

GA: l ~ 300GA: l ~ 300oo – 340 – 340oo

H-A filament: ~280H-A filament: ~280oo

Puppis filament: ~240Puppis filament: ~240oo

Local, Sag voids: Local, Sag voids: ~350~350oo – 52 – 52oo

New filament ~220New filament ~220oo

ZOA ZOA project project focused focused on low-on low-Galactic Galactic latitude latitude

skysky

Hydra wall andMonoceros extension

Puppis

Part of NormaSC

New

NewNew

PKS1343cluster

Puppisvoid

Extragalactic Arecibo L-Extragalactic Arecibo L-band Feed Array (ALFA) band Feed Array (ALFA) SurveysSurveys

Arecibo Legacy Fast ALFAArecibo Legacy Fast ALFA (ALFALFA) (ALFALFA) Team leaders: Giovanelli, Haynes (Cornell)Team leaders: Giovanelli, Haynes (Cornell)

Arecibo Galaxy Environments SurveyArecibo Galaxy Environments Survey (AGES) (AGES) Team leader: Davies (Cardiff)Team leader: Davies (Cardiff)

ALFA Ultra-Deep SurveyALFA Ultra-Deep Survey (AUDS) (AUDS) Team Team leader: Freudling (ESO)leader: Freudling (ESO)

Zone of Avoidance SurveyZone of Avoidance Survey (ALFA (ALFA ZOA) ZOA) Team leader: Henning (UNM)Team leader: Henning (UNM)

ALFALFAALFALFA

Arecibo Legacy Fast ALFA SurveyArecibo Legacy Fast ALFA Survey– 7000 deg7000 deg22 high-galactic latitude high-galactic latitude

Arecibo skyArecibo sky– ~2.2 mJy per 3.5 arcmin beam, at 10 ~2.2 mJy per 3.5 arcmin beam, at 10

km/s velocity resolutionkm/s velocity resolution– 100 MHz BW, -1600 – 18,000 km/s100 MHz BW, -1600 – 18,000 km/s– ~30,000 expected detections in ~5 ~30,000 expected detections in ~5

years, to z=0.06, hundreds of objects years, to z=0.06, hundreds of objects to HI mass to 10to HI mass to 1088

Team: 87 names, see ALFALFA website Team: 87 names, see ALFALFA website

ALFALFA science goalsALFALFA science goals

A legacy survey: HI in the Nearby UniverseA legacy survey: HI in the Nearby Universe The HI Mass Function and the “Missing The HI Mass Function and the “Missing

Satellite Problem”Satellite Problem” Galaxy evolution and dynamics within local Galaxy evolution and dynamics within local

large scale structures large scale structures Extent and origin of HI disks Extent and origin of HI disks Nature of High Velocity CloudsNature of High Velocity Clouds Blind survey for HI absorbers z < 0.06Blind survey for HI absorbers z < 0.06 Blind survey for OH megamasers 0.16 < z < Blind survey for OH megamasers 0.16 < z <

0.250.25 Comparison with other surveysComparison with other surveys

Catalogs, maps of selected Catalogs, maps of selected regions published, more regions published, more appearingappearing

No cosmologically important No cosmologically important pop of dark, HI galaxies pop of dark, HI galaxies (clouds in Virgo likely (clouds in Virgo likely remnants of interactions)remnants of interactions)

HIMF with 40% sample: HIMF with 40% sample: consistent with HIPASS, consistent with HIPASS, ΩΩHIHI 16% larger 16% larger

Z=0.05Z=0.05

Kent et al. 2009Kent et al. 2009

2700 HI sources plotted with 7.5% 2700 HI sources plotted with 7.5% of survey, much more has been doneof survey, much more has been done

40% ALFALFA HIMF, Martin et al. 201040% ALFALFA HIMF, Martin et al. 2010

– Study HI properties in different environments to Study HI properties in different environments to lower mass limits than ALFALFA (5 x 10lower mass limits than ALFALFA (5 x 1066 M MSunSun at at Virgo vs. 2 x 10Virgo vs. 2 x 1077 M MSunSun), low N), low NHI HI (3 x 10(3 x 101818 cm cm-2-2))

– HIMF in various environmentsHIMF in various environments– Spatial distribution of HI-selected objectsSpatial distribution of HI-selected objects– Low mass, low NLow mass, low NHIHI objects, and low- N objects, and low- NHIHI extent of extent of

large objectslarge objects– HVCsHVCs– Omega(HI)Omega(HI)– Signatures of mergers and interactions (tidal Signatures of mergers and interactions (tidal

features), relation to galaxy formation simulationsfeatures), relation to galaxy formation simulations

Davies, Auld, Baes, Bothun, Boselli, Brinks, BroschDavies, Auld, Baes, Bothun, Boselli, Brinks, BroschCatinella, Cortese, de Blok, Disney, Gavazzi, Giovanelli, Haynes,Catinella, Cortese, de Blok, Disney, Gavazzi, Giovanelli, Haynes,

Henning, Hoffman, Irwin, Karachentsev, Kilborn, Linder,Henning, Hoffman, Irwin, Karachentsev, Kilborn, Linder,Minchin, Momjian, Muller, O’Neil, Putman, Rosenberg, Minchin, Momjian, Muller, O’Neil, Putman, Rosenberg,

Sabatini, Schneider, Scott, Spekkens, van DrielSabatini, Schneider, Scott, Spekkens, van Driel

Arecibo Galaxies Environment Arecibo Galaxies Environment SurveySurvey

Simulation showing two Simulation showing two surveys, equal total surveys, equal total time, roughly same time, roughly same relative integration relative integration times of ALFALFA (red), times of ALFALFA (red), and AGES (blue)and AGES (blue)

Shallower detects more Shallower detects more sources, deeper detects sources, deeper detects lower mass sources at lower mass sources at all distancesall distances

ALFALFA excellent ALFALFA excellent probe of high-mass end probe of high-mass end of HIMF, but deeper of HIMF, but deeper surveys critical for low-surveys critical for low-mass end of HIMF in mass end of HIMF in environments beyond environments beyond Local SuperclusterLocal Supercluster

Schneider et al. 2008Schneider et al. 2008

#distinct vols sampled#distinct vols sampled

AGESAGES– 200 deg200 deg22 total on 13 selected areas (Virgo, total on 13 selected areas (Virgo,

groups, individual gals, filaments, Local Void, groups, individual gals, filaments, Local Void, also background volumes)also background volumes)

– ~0.8 mJy per 3.5 arcmin beam (300 vs. 40 ~0.8 mJy per 3.5 arcmin beam (300 vs. 40 sec per beam), at 10 km/s velocity resolutionsec per beam), at 10 km/s velocity resolution

– Finds low-mass galaxies to larger distances, Finds low-mass galaxies to larger distances, (eg. 5 x 10(eg. 5 x 1066 M MSunSun at Virgo, 5 x 10 at Virgo, 5 x 107 7 out to 3 out to 3 times this distance) but not as large-angle times this distance) but not as large-angle surveysurvey

Auld et al. 2006Auld et al. 2006

A1367 and outskirts, 5A1367 and outskirts, 5oo x 1 x 1oo strip strip 100 HI detections (100 HI detections (Cortese et al. 2008Cortese et al. 2008), 79 new. ), 79 new.

Solid line detection limit S/N=6.5, W=200 km/s, Solid line detection limit S/N=6.5, W=200 km/s, dotted line same for ALFALFA, dashed HIPASSdotted line same for ALFALFA, dashed HIPASS

HI does not HI does not show rich cluster show rich cluster

red is SDSSred is SDSSg < 17 magg < 17 mag

(L(Lgg > 2 x 10 > 2 x 1099 L LSunSun))

NGC 7332/7339 pair: 2 HI dwarfs discovered, have NGC 7332/7339 pair: 2 HI dwarfs discovered, have optical counterparts (5 total dwarfs)optical counterparts (5 total dwarfs)

MMHIHI 5 x 10 5 x 1077

MMHIHI/L/Lg g 2.0+-0.22.0+-0.2

MMHIHI 7 x 10 7 x 1077

MMHIHI/L/Lgg 0.13+-0.01 0.13+-0.01

Minchin et al. 2010Minchin et al. 2010

NGC 1156NGC 1156 D=7.8 Mpc D=7.8 Mpc

(Karachentsev et al.)(Karachentsev et al.) isolated, no isolated, no cataloged cataloged companion within companion within 10 deg 10 deg

AGES: MAGES: MHIHI = 1 x = 1 x 101099 M MSun, Sun, and new and new dwarf 25 arcmin dwarf 25 arcmin away, Maway, MHIHI = 1.6 x = 1.6 x 10106 6 MMSun Sun , , counterpart on counterpart on DSSDSS

Minchin et al. 2010Minchin et al. 2010

Total co-moving volume 24,000 MpcTotal co-moving volume 24,000 Mpc33: 82 : 82 galaxies, 45 new discoveries, few previously galaxies, 45 new discoveries, few previously known redshiftsknown redshifts

Known Known voidsvoids

Two sheetsTwo sheets

Minchin et al. 2010Minchin et al. 2010

LSLSSS

HI mass versus distance with SNR HI mass versus distance with SNR = 5, cp. ALFALFA (dotted)= 5, cp. ALFALFA (dotted)Red for NGC 1156 region, black Red for NGC 1156 region, black NGC 7332/7339 regionNGC 7332/7339 region

AGES Virgo fieldsAGES Virgo fieldsRhys Taylor thesis, Rhys Taylor thesis,

CardiffCardiff

No dark galaxiesNo dark galaxies 30% of HI detections not in optical VCC. Small, faint, blue30% of HI detections not in optical VCC. Small, faint, blue 21 new detections vs. 270 VCC galaxies21 new detections vs. 270 VCC galaxies Detected S0’s fainter, redder, less gas than S, show some Detected S0’s fainter, redder, less gas than S, show some

structure, transition region CMD, evolved by gas loss?structure, transition region CMD, evolved by gas loss? Detected dE’s comparable MDetected dE’s comparable MHIHI/L to dIrr’s – recently /L to dIrr’s – recently

accreted?accreted? Virgo still assembling, gas-rich dwarfs interspersed with Virgo still assembling, gas-rich dwarfs interspersed with

HI-deficient giant spirals HI-deficient giant spirals No direct evidence of stripped gas (stacking) <5 x 10No direct evidence of stripped gas (stacking) <5 x 101717, ,

ionized?ionized?

HI dets HI dets outlined in outlined in

blue,blue,Non-dets Non-dets

in red, in red, VC1VC1

Blue Blue background,background,

Red VC Red VC membersmembers

Cold Gas Evolution

The ALFA Ultra-Deep Survey AUDS

0.36 square degrees 2 fields, 1 within AGES NGC 2577 survey, 1 random at ra=17, dec=20 “drift & chase”: repeated drift scans, 1000 hours 200 MHz => 0 < z < 0.16 sensitivity 50 Jy corresponds to a few 109M precursor program of 60 hours demonstrated feasibility

Freudling, Brinks, Brosch, Catinella, Conselice, Davies, de Blok, Kilborn, Linder, Masters, Meyer, Minchin, Momjian, O'Neil, Pisano, Quinn, Rosenberg, Spekkens, Staveley-

Smith, van Driel, Zwaan

Precursor observations detected 18 Precursor observations detected 18 galaxies between z = 0.07 – 0.15galaxies between z = 0.07 – 0.15

Freudling et al. 2010Freudling et al. 2010

Result: detection rate consistent Result: detection rate consistent with z=0 HIMFwith z=0 HIMF

Green solid line: local HI mass function. Dashed is corrected for overdensity of SDSS volume.

Solid points = all detections

Open points = high quality detections

ρHI (z=0.125) = 1.0 ± 0.3 ρHI (z=0)

Freudling et al. 2010

ALFA Zone of AvoidanceALFA Zone of Avoidance Henning, McIntyre, Day, Springob, Minchin, Momjian, Catinella, Muller, Henning, McIntyre, Day, Springob, Minchin, Momjian, Catinella, Muller,

Koribalski, Masters, Pantoja, Putman, Rosenberg, Schneider, Staveley-Koribalski, Masters, Pantoja, Putman, Rosenberg, Schneider, Staveley-Smith, van DrielSmith, van Driel

Obscuration due to dust, high stellar density of MW blocks optical Universe Obscuration due to dust, high stellar density of MW blocks optical Universe over ~20% of skyover ~20% of sky

2MRS retains ZOA of several deg width in outer Galaxy, tens of deg in inner 2MRS retains ZOA of several deg width in outer Galaxy, tens of deg in inner Galaxy, forcing statistical treatment of missing data for reconstruction of Galaxy, forcing statistical treatment of missing data for reconstruction of density and velocity fieldsdensity and velocity fields

Misalignment CMB dipole vs. 2MASS flux-weighted dipole, evidence for Misalignment CMB dipole vs. 2MASS flux-weighted dipole, evidence for unmapped mass, esp. behind inner Galaxyunmapped mass, esp. behind inner Galaxy

Goal: Map hidden galaxies, LSS in HIGoal: Map hidden galaxies, LSS in HI Those with NIR counterparts – provide z, Tully-Fisher, flow fieldsThose with NIR counterparts – provide z, Tully-Fisher, flow fields Done commensally, with Galactic ALFA and Pulsar ALFADone commensally, with Galactic ALFA and Pulsar ALFA

Precursor: 38 degPrecursor: 38 deg22 near l=40, 100 deg near l=40, 100 deg22 near l=190 (Henning et near l=190 (Henning et al. 2010)al. 2010)Inner Galaxy: 10 galaxies detected, only 1 has a catalogedInner Galaxy: 10 galaxies detected, only 1 has a catalogedcounterpart in any other waveband (IR) counterpart in any other waveband (IR) Outer Galaxy: 62 galaxies detected, 49 have counterparts Outer Galaxy: 62 galaxies detected, 49 have counterparts 25 previous redshifts25 previous redshifts

LSS in outer Galaxy – concentration at LSS in outer Galaxy – concentration at ll ~ 183 ~ 183oo, b ~ -10, b ~ -10oo, , between 5000-6000 km/s (~5hr), lies near Orion concentration between 5000-6000 km/s (~5hr), lies near Orion concentration and feature “C5” in 2MRS density field reconstruction (Erdogdu and feature “C5” in 2MRS density field reconstruction (Erdogdu et al. 2006). Voids evident.et al. 2006). Voids evident.Full survey of AO ZOA underway, expect thousands of galaxies!Full survey of AO ZOA underway, expect thousands of galaxies!

Precursor resultsPrecursor results

Beyond ALFABeyond ALFA

Current generation ALFA surveys will yield Current generation ALFA surveys will yield ~several x 10~several x 1044 galaxies to z~0.1, will galaxies to z~0.1, will characterize the local HI mass function very well. characterize the local HI mass function very well.

HI detection beyond z = 0.1 has been achieved: HI detection beyond z = 0.1 has been achieved: – direct at z=0.2+ with WSRT (Verheijen et al.), direct at z=0.2+ with WSRT (Verheijen et al.),

AO (Catinella et al.) AO (Catinella et al.) – Stacking at z=0.24, 0.37 with GMRT (Lah et Stacking at z=0.24, 0.37 with GMRT (Lah et

al.), z=0.8 with GBT (Chang et al. 2010).al.), z=0.8 with GBT (Chang et al. 2010).

Star formation rate has evolved dramatically since z~1Star formation rate has evolved dramatically since z~1 Predictions of smaller evolution of cold gas content z < 2 due Predictions of smaller evolution of cold gas content z < 2 due

to self-regulated equilibrium between net gas inflow and SFto self-regulated equilibrium between net gas inflow and SF Want detailed account of HI over redshift with large evolution Want detailed account of HI over redshift with large evolution

in SFR – where, how, is gas going to stars?in SFR – where, how, is gas going to stars?

Hopkins & Beacom Hopkins & Beacom 20062006

Noterdaeme et al .2009Noterdaeme et al .2009

The action at high zThe action at high z

Progress: Progress: existing/upgraded,existing/upgraded,new facilitiesnew facilities Existing/upgraded/new facilitiesExisting/upgraded/new facilities– WSRT/APERTIF, FPA on WSRT, 8 degWSRT/APERTIF, FPA on WSRT, 8 deg22 FOV, 300 MHz FOV, 300 MHz

BWBW– EVLA, z=0-0.5EVLA, z=0-0.5– GMRT, GBT stacking GMRT, GBT stacking – AO, a 10% SKA in area, niche local-intermediate z, AO, a 10% SKA in area, niche local-intermediate z,

confusion an issue at high z: beam about size of a confusion an issue at high z: beam about size of a cluster at z = 0.25. AO40cluster at z = 0.25. AO40

– ATA, 42 6m dishes, FoV 2.5 deg at 21cm. ATA, 42 6m dishes, FoV 2.5 deg at 21cm. – FASTFAST

New interferometers – SKA precursorsNew interferometers – SKA precursors– MeerKATMeerKAT– ASKAPASKAP

Ultimately, SKAUltimately, SKA

MeerKATMeerKAT– 64 13.5m dishes, single pixel feeds64 13.5m dishes, single pixel feeds– Majority of dishes within 1 km, others to 8 km Majority of dishes within 1 km, others to 8 km

(+spur?)(+spur?)– Primary beam ~1Primary beam ~1oo

– 0.9 – 1.75 GHz initially, 0.6 – 2.5 GHz (+high 0.9 – 1.75 GHz initially, 0.6 – 2.5 GHz (+high freq) later, 30 Kfreq) later, 30 K

– HI Niche: sensitivity, resolution HI Niche: sensitivity, resolution – Approved projects include Approved projects include

MeerKAT ultradeep HI, 5000 hours. Direct detection MeerKAT ultradeep HI, 5000 hours. Direct detection to z~0.5, stacking z~1 (Blyth, Holwerda, Baker to z~0.5, stacking z~1 (Blyth, Holwerda, Baker +team)+team)

sensitive nearby galaxies survey, 6000 hours. 30 sensitive nearby galaxies survey, 6000 hours. 30 galaxies to Ngalaxies to NHIHI ~ 10 ~ 1019 19 (30(30””), 5x10), 5x1017 17 (90(90””) (de Blok + ) (de Blok + team)team)

Much more on this tomorrow from Blyth and de Blok!Much more on this tomorrow from Blyth and de Blok!

Australian SKA Pathfinder (ASKAP)Australian SKA Pathfinder (ASKAP) – 36 12-m antennas 36 12-m antennas – 700-1800 MHz 700-1800 MHz – Max baseline 6 km Max baseline 6 km – PAFs: PAFs: FOV 30 deg2 – Approved projects include:

– Widefield ASKAP L-band Legacy All-sky Blind Widefield ASKAP L-band Legacy All-sky Blind SurveY SurveY (Koribalski, Staveley-Smith + team)(Koribalski, Staveley-Smith + team)

-90-90oo < Dec < +30 < Dec < +30oo Typical depth z=0.05, massive galaxies to z = 0.15Typical depth z=0.05, massive galaxies to z = 0.15 ~500,000 detections~500,000 detections

– Deep Investigations of Neutral Gas Origins Deep Investigations of Neutral Gas Origins (Meyer (Meyer + team)+ team)

150 deg150 deg22 deep field (z<0.29), 60 deg deep field (z<0.29), 60 deg2 2 ultradeep ultradeep (z<0.4), (GAMA region; spectroscopy, imaging from UV-(z<0.4), (GAMA region; spectroscopy, imaging from UV-IR)IR)

~10~1055 HI sources for 7500 hrs of combined observing time HI sources for 7500 hrs of combined observing time

Z=0.0Z=0.055 Johnston et al. 2007Johnston et al. 2007

Baseline, Baseline, UpgradeUpgrade

Z=0.2Z=0.2

Square Kilometer ArraySquare Kilometer Array Existing and near-term facilities will push to Existing and near-term facilities will push to

intermediate z, do pathfinding science work for intermediate z, do pathfinding science work for ultimate deep, hi-res SKA surveysultimate deep, hi-res SKA surveys

HI at cosmological distances original driver HI at cosmological distances original driver toward ~1 kmtoward ~1 km2 2

Halo clouds beyond Virgo, discriminate Halo clouds beyond Virgo, discriminate between modes of cold gas accretion, and between modes of cold gas accretion, and any HI beyond z=1 requires SKAany HI beyond z=1 requires SKA

MW to z~1.5 in all-sky survey, to z~2-3 in MW to z~1.5 in all-sky survey, to z~2-3 in deep surveydeep survey

SKA DRMSKA DRM

Angular resolution: eg. 2” corresponds to Angular resolution: eg. 2” corresponds to ~15 kpc at z=2 (60 km baseline at 500 MHz), ~15 kpc at z=2 (60 km baseline at 500 MHz), exquisite detail in local Universe exquisite detail in local Universe

Connection to multi-Connection to multi-large optical/IR large optical/IR surveys going concerns in the coming years, surveys going concerns in the coming years, time will be ripe for deep HI surveystime will be ripe for deep HI surveys

Today, surveys of HI in galaxies in infancy cp Today, surveys of HI in galaxies in infancy cp to large optical surveys. With SKA, bring HI to large optical surveys. With SKA, bring HI picture to maturitypicture to maturity

Thanks!Thanks!