HI Galaxies & the Star Formation Rate-Density Relation Dr Marianne T. Doyle - My PhD Michael J. Drinkwater – UQ - Principle Advisor Elaine Sadler, Uni Sydney & John Ross - Assoc. Advisors

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney Content Morphology-Density & Star Formation Rate-Density Relations A New way to Investigating the SFR-Density Relation - HI Galaxy Sample HI Parkes All Sky Survey Optical Catalogue HOPCAT Results Conclusions What Next? ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney In The Beginning……… SFR -Density Relation Lewis et al (2002) Morphology -Density Relation Dressler et al. (1980) ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney My PhD Project Past studies are based on optical samples Different Investigation of SFR-Density Relation - HI Galaxies Sample to answer the question: Are there fewer HI “star forming” galaxies in regions of high galaxy density OR Are there physical processes that directly suppresses star formation in these galaxies? FIND NO STAR FORMING GALAXIES OR VERY FEW IN GALAXY DENSE REGIONS FIRST PROVED FIND HI BUT NO STAR FORMATION THEN 2ND IS RIGHT ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney Local Galaxy Density 3D Local Galaxy Density → No Redshifts → Not Possible 2D - Local Surface Density – Σ10 HIPASS Catalogue (HICAT) Optical Catalogue - HOPCAT Reliable radio-optical galaxy matches Centred on HICAT positions HICAT Information ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

Star Formation Rate & Efficiency Star Formation Rate – SFR Infrared Fluxes from IRAS Radio Fluxes from SUMSS & NVSS Star Formation Efficiency - SFE ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney SFR-Density Relation Infrared SFRs SFR-Density Relation Radio SFRs ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney SFR-Density Relation Infrared SFRs Separated into 1000 km s-1 Velocity Ranges 6dF2MASS-IRAS 1180 galaxies SFR-Density Relation Radio SFRs Separated into 1000 km s-1 Velocity Ranges SCosGC-SUMSS/NVSS 339 galaxies 339 (172 & 167) 478 (275 & 203) ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney SFE-Density Relation Infrared SFEs Separated into 1000 km s-1 Velocity Ranges 6dF2MASS-IRAS 1180 galaxies SFE-Density Relation Radio SFEs Separated into 1000 km s-1 Velocity Ranges SCosGC-SUMSS/NVSS 339 galaxies ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney Optical vs. Radio Samples KS test confirms 2 populations are different ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

Comparing SFR vs. Σ10 Results ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney Conclusion So…….. SFR & SFE of HI Galaxies does not depend on Σ10 Population of HI galaxies decreases with increasing Σ10 compared to past optical samples There are fewer HI star-forming galaxies in regions with increasing local surface density. It is the HI galaxy population that decreases, not their SFR, with increasing local surface density. Confirming the Morphology-Density Relation. Previous SFR-Density Relation results are due to the optical data samples used. ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

PhD completed! (Sigh of relief) Wish List for Post Doctoral Research? Star Formation in Galaxies &/or Galaxy Groups/Clusters. Intergalactic galaxy/cluster research. SKA/Radio Astronomy. Multi-wavelength extragalactic research. Optical Astronomy. To be or not to be a Dark Galaxy…….. ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney EXTRA SLIDES ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

A New way to Investigating the SFR-Density Relation – HI Galaxies HI Galaxy Sample - HOPCAT Optical Catalogue based on the HI Parkes All Sky Survey Catalogue (HICAT) Original HICAT parameters 6dF & NED velocities SuperCOSMOS Image Centred on HICAT positions ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

Local Galaxy Density Problems? Density Corrections for edge affects > 50% edge affected - galaxy removed Density Corrected Northern & Galactic Plane edge affected – trigonometry SMC & LMC edge affected – Monte Carlo integral method No redshifts – Fore & Background galaxy contamination? Arbitrary MBj bright & faint limits (-21&-17mags respectively) Corresponding mbj limits calculated using target galaxies velocity Only use galaxies with this range of mbj ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

Star Formation Rate & Efficiency Radio & Infrared Fluxes Infrared Fluxes from IRAS Radio Fluxes from SUMSS & NVSS ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney Data Sets Fluxes HOPCAT-SCosGC HOPCAT-6dF2MASS SFR vs MHI (vel<10000 km s-1) IRAS 1405 1405 SUMSS 340 340 SN6I 221 221 Σ10 Plots ( 1000<vel<6000 km s-1) IRAS 923 1180 SUMSS 172 275 SN6I 167 203 ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney HI Mass vs. SFR But is this to good to be true? Flux Limited Sample? ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney

ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney HI Mass vs. SFR Separated into 1000 km s-1 Velocity Ranges ASA Scientific Meeting 1 – 5th July, 2007 Macquarie University, Sydney