The HICAT Optical CatalogueHOPCAT

Marianne T. DoylePh.D. Project

Content

Input Data

Matching Process

Magnitude Calibration

Results

Candidate Dark Galaxies?

Supervisor:Michael J. Drinkwater – UQAssoc. Supervisors:Elaine Sadler – Uni SydneyJohn Ross - UQCollaborators David J. Rohde - UQMike Read – WFAU

EdinburghBaerbel Koribalski – ATNF,

EppingHIPASS Team – ATNF Parkes

& Epping, Universities of : Melbourne, Cardiff, Western Sydney Macarthur, Wales, Swinburne, Technology Sydney, New Mexico, Manchester, Colorado, Sydney, LeicesterASTRON The Netherlands,AAO Sydney,WIYN Tucson etc….......

RADIO DATA HIPASS Catalogue - HICAT - 4315 radio HI detected sources

Meyer et. Al 2004 (Paper I ) & Zwaan et. Al 2004 (Paper II )

OPTICAL IMAGES SuperCOSMOS 15’ x 15’ Images 7’ radius Radio-Optical

position uncertainty IMAGE ANALYSIS SExtractor Image Analysis

SuperCOSMOS data catalogue? Ellipse segmentation problem for extended objects

SExtractor Segmentation problems?Used 2 sets of ellipse analysis parameters

Input Data

Radio-Optical Position Uncertainty

Input Data Velocities to Confirm Optical Matches

NED (NASA/IPAC Extragalactic Database)Only optical and high resolution radio

measured velocities used 6dFGS

Non-public data as at 4th September, 2003

Hicat sources were included in survey

Matching Process ADRIC Interactive Program written by David Rohde Find optical counterpart by choosing galaxy ellipse by:

Confirming HICAT velocities with published velocitiesWithout velocity confirmation

Only galaxy in imageProximity to HICAT position Velocity width ….

Visually matched by 3 peopleMarianne DoyleMichael DrinkwaterDavid Rohde

Superimposed ellipses

Yellow for correct match

15 x 15 arcmin images to allow

for the 7 arcmin position uncertaintyCentred on

HICAT positions

Selection parameters

Original

HICAT parameters

Superimposed and listedPublished velocities

Magnitude Calibration SuperCOSMOS data catalogue - Calibrated

SExtractor magnitudes - Uncalibrated

Use the relationship between the SuperCOSMOS &

SExtractor magnitudes for calibration

SuperCOSMOS Plate to Plate differences/Zero-point

calibration Analysed every object of 4315 blue images

Matched Galaxies To calculate magnitude calibration

values

Velocity Match 44% 1882 With published velocity

Good Guesses 20% 851 But no published velocity

Velocity Multi Match 14% 634 Compact group of galaxies with published velocity

Good Guess Multi Match 6% 256 Compact group of galaxies no velocity

No Guess 11% 476 Several galaxies no velocities

Blank Field 5% 216 No visible galaxy

ResultsAnalysis of 4315 Radio Sources - 84% identified

Log HIPASS Peak Flux Vs Optical Apparent MagnitudeObjects matched by published velocities, educated guesses without

velocity and velocity matches where multiple galaxies match.

Integrated Radio flux and Apparent Blue Magnitudes Totally

independent variables

Correlation shown

Higher the blue magnitude - Higher Radio Flux

HICAT Vs HOPCAT Position Uncertainties

Difference between Radio and Optical Positions Velocity Matched

Position difference between the synthetic point sources & the fitted position after parameterization

(Zwaan et.al 2004)

Extinction Cut at 0.6

Candidate Dark Galaxies? 65 Possible but 58 in crowded fields 7 possible candidates for dark galaxies?

1 possibly HVC with ATCA Observation by Rachel Webster HIPASSJ1351-46 Vel=528 km s-1 (C638)

2 previously observed at ATCA by Bärbel KoribalskiHIPASSJ0940-42 Vel = 2268 km s-1 (C942)HIPASSJ0902-40 Vel = 1636 km s-1 (C781)

4 remaining HICAT Name Velocity (km s-1)

Extinction (Schlegel)

HIPASSJ1946-48 7730 0.0402

HIPASSJ1317-73 5666 0.286

HIPASSJ0643-16 2797 0.5503

HIPASSJ1638-15 7457 0.5096

HIPASSJ1946-48

B=349.7205˚

L=-28.8053˚

Vel=7730 km s-1

Ext= 0.0402

MHI=1.3x1010Msolar

Optical matching process

CompletedHOPCAT

Use Infrared & Radio

Continuum to measure SFR

Determine local galaxy

density

ATCA 21cm high resolution observation

Feb 24-27 & March 3-9 2005

178.5 hours All helpers with

observing welcome!!!!

What’s Next

Calculate SFE &

relate to galaxy

morphology

Determine which theory contributes toward the

Morphology-density relation

HIMass

SFRSFE

Lagoon Nebula100LY across

Contains many young stars

& hot gas

Thank you for your attention

Difference between Radio and Optical Positions for Velocity Matches

Difference between Radio and Optical Positions for Good Guesses

Radio-Optical Separations

50

Radio-Optical Separations

50Difference between Radio and Optical Positions for Velocity Matches

Difference between Radio and Optical Positions for Multiple Velocity & Good Guesses Matches

HI Peaks

Optical Peak

Position

Radio-Optical Position Difference

Candidate Dark Galaxies?

Hipass NameRa(h:m:s)

Dec(d:m:s)

vel_mom(km s-1)

Sint(Jy kms-1)

l(degree)

b(degree) Extinction

Density to 10th Galaxy(Gal/deg2)

Mass HI(Msolar)

HIPASSJ1317-73 13:17:40.3 -73:09:42 5666.7 3.8 304.8596 -10.3882 0.286 0.0184 5.7E+09

HIPASSJ1946-48 19:46:05.4 -48:54:35 7730.4 4.8 349.7205 -28.8053 0.0402 2.5939 1.3E+10

HIPASSJ1351-46(HVC) 13:51:18.9 -46:58:25 528.8 3.5 313.4294 14.674 0.1436 0.0994 4.6E+07

HIPASSJ0940-42(ATCA) 09:40:16.8 -42:56:56 2268.7 4.8 269.7996 7.2958 0.4938 0.0174 1.2E+09

HIPASSJ0902-40(ATCA) 09:02:02.6 -40:06:40 1636.6 12.2 262.7154 4.2126 0.5586 0.0112 1.5E+09

HIPASSJ0643-16 06:43:59.0 -16:07:33 2797.6 8.5 226.5693 -8.8849 0.5503 0.0242 3.1E+09

HIPASSJ1638-15 16:38:02.9 -15:37:48 7457.2 8.5 2.047 20.3829 0.5096 0.1955 2.2E+10

HIPASSJ1317-73

b = 304.8596˚

l = -10.3882˚

Vel=5666 km s-1

Ext= 0.286

MHI=5.7x109Msolar

HIPASSJ0643-16

b = 226.5693˚

l = -8.8849 ˚

Vel =2797 km s-1

Ext = 0.5503

MHI=3.1x109Msolar

HIPASSJ1638-15

b = 2.047˚

l = 20.3829˚

Vel=7457 km s-1

Ext= 0.5096

MHI2.2x1010Msolar