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Observations of HIPASS radio galaxies with 6dF

Michael Drinkwater, Melbourne(for the multibeam working group) 1 The HI Parkes All-Sky Survey

HI Mass Function vs. optical morphological type Star formation efficiency vs. environment Optical counterparts for 6dF

2 Gravitational Lenses in the 6dF GS

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Catalogue Properties

(Kilborn 2001)

HIPASS: 21cm line neutral hydrogen < +2 [< +22 northern] 1200 12,700 kms-1 ~13 mJy RMS

Expect ~5200 detections, cf: ZOA ~1000, BGals 1000, SC

~500 Rosenburg & Schneider (2000):

265 Spitzak & Schneider (1998): 75 Henning (1995): 37

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Catalogue details

HIPASSJ0607-61

Two algorithms to detect candidates: Artificial sources added to measure completeness ‘MultiFind’ (Kilborn): 4 peak flux detection

detection in 2 adjacent velocity planes Hanning smooth, repeat 2

‘TopHat’ (Howlett) cross correlate spectra with top hat filter repeat: filter sizes 1-40 velocity channels

Candidate lists merged Automatic cleaning

reject -300 < VGSR < 300 reject lines at known interference freqs

Interactive checking & parameter fitting accurate velocity, widths, fluxes

Example Detections

Velocity (km s-1)

Flux

Den

sity

(Jy)

HIPASS J2232-46

Velocity (km s-1)

Flux

Den

sity

(Jy)

HIPASS J2202-20

Velocity (km s-1)

Flux

Den

sity

(Jy)

HIPASS J0246-30

Velocity (km s-1)

Flux

Den

sity

(Jy)

HIPASS J1035-24

Parameter Distributions

velocity (km s-1) width (km s-1)

peak flux (Jy) number of detections per cube

Galaxy Distribution

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Catalogue Applications

HI Mass Function (Zwaan)

HI Column Density (Ryan-Weber)

Local Groups (Stevens)

HIP 1723-80

Group Members

Velocity (ms-1)

Flux

(Jy/

beam

)

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Catalogue Applications

• Inclination > 500 • Sb-Sc & SBb-SBc

Tully-Fisher (Meyer) Correlation Function (Tantisrisuk)

S (h Mpc)

1 +

(s)

(r/r0)-

r0 = 3.55 = 1.7

Rotational Velocity [log(v50max)]

Mag

nitu

de [

ki20

e - 5

log(

v/10

0) -2

5]

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Catalogue Applications

Unusual objects, eg no optical counterpart (Kilborn, Koribalski)

Survey sample selection, eg SINGG (Meurer et. al.)

HIP J1712-64

HIP 976 (IC5332)

Right Ascension (J2000)

Dec

linat

ion

(J20

00)

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Status Spectra on line at www.atnf.csiro.au/research/multibeam draft catalogue completed

Papers in preparation I. Parkes HI Catalogue II. Completeness Analysis III. Optical properties

15 arcmin beam 4 arcmin position errors high resolution ATCA image OR optical

redshift

Catalogue Status

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HI mass distributionLow-mass slope of HI mass

function (HIMF) HI mass function optical

luminosity function most baryonic mass in low

surface brightness HI-detected galaxies?

steeper slope than other studiesMass [log MHI/Msun]

Den

sity

[M

pc-3de

x-1]

HIMF as a function of optical morphology neutral gas morphology environment is morphology driven by formation conditions or

later interactions with environment?

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Star formation efficiency NIR + optical

Star formation past and present

HIPASS (HI) remaining fuel

star formation future

failed star formation

SF efficiency as a function of environment density-morphology relation (Dressler 1980): decrease in %

of late-type (SF) galaxies in regions of high galaxy density test models of the density-morphology relation using data

not biased by current star formation

Optical H NIR

HI total HI V HI velocity

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HIPASS 6dF Sample

Aim: optical identification of HIPASS 4 arcmin position uncertainties traditional solution: high resolution radio

imaging not realistic for 5000 sources! statistical solution: measure redshifts for all

possible matching galaxies then match by velocity

6dF: not complete but should match majority bonus: synergy with 6dF and 2MASS science

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HIPASS 6dF SampleOptical identification using 6dF redshifts

optical redshifts of any possible matches 6dF already doing galaxies R<15.7 HIPASS |b|>10 deg, Dec<0 deg; N=5800 matched to SuperCOSMOS “galaxies” N=66132

15.6<R<17 & closer than 5 arc min (Mike Read, WFAU) automatic and manual cleaning N=2710 4 peak flux limit (50 mJy) N=1195 additional target total N=717

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HIPASS matches: SuperCOSMOS R-band 1arcmin images

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Summary of outcomes

1. Optical IDs (catalogue paper III) statistical first pass using position

matches to SuperCOSMOS sky catalogues improve with colour and morphology

2. 6dF identifications (in 3-4 years) best solution using redshift matches detailed analysis of density-morphology

relation

2. Gravitational Lenses in the 6dF GS

Rosetta Stone of lensing: QSO2237+050 (Huchra et al 1985)

lens: z=0.04 spiral galaxy

model (C. Trott): core of dark matter profile is flat, not cuspy

any of these in the 6dF GS?

total rotation curve

dark matter

disk

bulge

bar

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Gravitational Lenses in the 6dF GS

Detection statistics galaxies + magnified QSOs preferentially

selected in flux-limited galaxy surveys but QSO counts drop rapidly at brighter limits 2dF GRS (2.5 105) ~10 lensed galaxies SDSS (106) ~100 lensed galaxies

(Mortlock & Webster 2000) 6dF (105) ~1 lensed galaxies but ~10 if QSOs as red as B-K=8

(Mortlock & Drinkwater 2001)

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Gravitational Lenses in the 6dF GS

Search of 2dF GRS: search underway at Cambridge 2 good candidates: not confirmed lenses D. Mortlock, P. Hewett & D. Madgwick

Search of 6dF GS: same software will be used when 6dF data released!