The HICAT Optical Catalogue HOPCAT

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The HICAT Optical CatalogueHOPCAT

• Marianne T. Doyle
• Ph.D. Project

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Content
Supervisor Michael J. Drinkwater UQ Assoc.
Supervisors Elaine Sadler Uni Sydney John Ross
- UQ Collaborators David J. Rohde - UQ Mike
Read WFAU Edinburgh Baerbel Koribalski ATNF,
Epping HIPASS Team ATNF Parkes Epping,
Universities of Melbourne, Cardiff, Western
Sydney Macarthur, Wales, Swinburne, Technology
Sydney, New Mexico, Manchester, Colorado, Sydney,
Leicester ASTRON The Netherlands, AAO
Sydney, WIYN Tucson etc.......

• Input Data
• Matching Process
• Magnitude Calibration
• Results
• Candidate Dark Galaxies?

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Input Data

• 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

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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

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Matching Process

• ADRIC Interactive Program written by David Rohde
• Find optical counterpart by choosing galaxy
  ellipse by
• Confirming HICAT velocities with published
  velocities
• Without velocity confirmation
• Only galaxy in image
• Proximity to HICAT position
• Velocity width .
• Visually matched by 3 people
• Marianne Doyle
• Michael Drinkwater
• David Rohde

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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

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ResultsAnalysis of 4315 Radio Sources - 84
identified

• 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

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• Integrated Radio flux and Apparent Blue
  Magnitudes
• Totally independent variables
• Correlation shown
• Higher the blue magnitude - Higher Radio Flux

Log HIPASS Peak Flux Vs Optical Apparent
Magnitude Objects matched by published
velocities, educated guesses without velocity and
velocity matches where multiple galaxies match.
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HICAT Vs HOPCAT Position Uncertainties
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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 Vel528 km s-1 (C638)
• 2 previously observed at ATCA by Bärbel
  Koribalski
• HIPASSJ0940-42 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

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• HIPASSJ1946-48
• B349.7205
• L-28.8053
• Vel7730 km s-1
• Ext 0.0402
• MHI1.3x1010Msolar

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Whats Next

• ATCA 21cm high resolution observation
• Feb 24-27 March 3-9 2005
• 178.5 hours
• All helpers with observing welcome!!!!

Optical matching process Completed HOPCAT
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Thank you for your attention
Lagoon Nebula 100LY across Contains many young
stars hot gas
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Radio-Optical Separations
50
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Radio-Optical Separations
50
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Radio-Optical Position Difference
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Candidate Dark Galaxies?
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• HIPASSJ1317-73
• b 304.8596
• l -10.3882
• Vel5666 km s-1
• Ext 0.286
• MHI5.7x109Msolar

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• HIPASSJ0643-16
• b 226.5693
• l -8.8849
• Vel 2797 km s-1
• Ext 0.5503
• MHI3.1x109Msolar

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• HIPASSJ1638-15
• b 2.047
• l 20.3829
• Vel7457 km s-1
• Ext 0.5096
• MHI2.2x1010Msolar