1 / 18

Radio sources in the 6dFGS Tom Mauch & Elaine Sadler University of Sydney

Radio sources in the 6dFGS Tom Mauch & Elaine Sadler University of Sydney. LAST YEAR:. ‘Main survey’ science: Faint end of radio luminosity function for AGN, starbursts Accurate z=0 benchmarks for studies of cosmic evolution

arden
Télécharger la présentation

Radio sources in the 6dFGS Tom Mauch & Elaine Sadler University of Sydney

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Radio sources in the 6dFGS Tom Mauch & Elaine Sadler University of Sydney LAST YEAR: • ‘Main survey’ science: • Faint end of radio luminosity function for AGN, starbursts • Accurate z=0 benchmarks for studies of cosmic evolution • Black hole mass/velocity dispersion relation for radio AGN • ‘Extratargets’ science: • Compact objects and some galaxies with blue colours (QSOs, starburst galaxies…) 6dF workshop

  2. All-sky radio continuum surveys NVSS(Condon et al. 1998) n = 1.4 GHz dec +90o to -40o SUMSS (Bock et al. 1999; Mauch et al. 2003) n = 843 MHz dec -30o to -90o Currently almost 85% complete (though not catalogued), will be finished by Dec 2003 Both surveys have 45” beam, 3-6 mJy det. limit, position accuracy 1-2” 6dF workshop

  3. Since Last Year: • ~ 6% of 6dFGS galaxies in initial data release are detected as radio sources. • 909 Radio sources in 14880 galaxies. • 394 Additional Target spectra. • All spectra eyeballed and classified. • Initial database of radio detections with multiwavelength data. 6dF workshop

  4. The Database Convenient method for searching large dataset! 6dF workshop

  5. Radio sources in the main survey: • 909 radio sources out of 14880 total objects • 6% Detection Rate! • Possibly because of our 10” radio optical separation cutoff. • All spectra hand classified (star,Aa,Ae,Aae,SF): • 399 AGN • 436 Star-Forming • 71 Unclassifiable • 3 Stars • About 50/50 split between AGN and SF in 6dFGS • (60/40 in 2dFGS) 6dF workshop

  6. Typical Spectra of Faint radio Sources in 6dFGS (1) • Absorption line AGN: 6dF workshop

  7. Typical Spectra of Faint radio Sources in 6dFGS (2) • Emission Line AGN: 6dF workshop

  8. Typical Spectra of Faint radio Sources in 6dFGS (3) • Star Forming Galaxies: IRAS Source 0.28 Jy at 60mm Large fraction of SF galaxies interacting. 6dF workshop

  9. Redshift distribution of 6dFGRS radio sources 2dF Sample 6dF Sample 6dF workshop

  10. Radio emission from star-forming galaxies 6dFGS-NVSS 2dFGS-NVSS Many faint (<5mJy) NVSS sources with no IRAS detection. 6dF workshop

  11. Local radio luminosity function of active and star-forming galaxies Distribution of AGN radio luminosities. Low-luminosity AGN are hard to find 6dF workshop

  12. 6dFGS ‘Additional targets’ • 6dFGS unallocated fibres placed on NVSS/SUMSS radio IDs which have bJ<18 mag but which are not in the main sample: • 394 objects in initial data release. • Stellar objects (foreground stars, QSOs, compact galaxies) • Blue galaxies (starburst, AGN) • What fraction of the local radio-source population is missed because hosts appear stellar? Don’t need all objects observed, just a sub-sample - i.e. flexible 6dF workshop

  13. Detection fractions of additional targets • Many additional targets are in other additional target samples, large fraction have been observed! • 166 stars • 61 AGN • 74 Star Forming • 93 Unknown About same fraction as in main survey! Possible BL-Lac population. 6dF workshop

  14. Redshift Distribution of Additional Target Galaxies • Median z=0.08 • Fainter sources • Emission line AGN • Starburst galaxies 6dF workshop

  15. Some interesting Additional Targets (1): • QSO- No previously recorded redshift. • Bright radio source (1.8 Jy in NVSS) also PKS 1955-35 6dF workshop

  16. Some interesting Additional Targets (2): • Higher-z QSO (4.9 mJy at 1.4 MHz) • Incorrect z from runz; actual z is 0.75 MgII 6dF workshop

  17. Some interesting Additional Targets (3): • Starburst Galaxy (ULIRG?) 43.5 mJy at 1.4 GHz (1024.5 W Hz-1) 0.189 Jy at 60mm 6dF workshop

  18. Some interesting Additional Targets (4): • Radio emission from white dwarfs? • Willes & Wu 2003 (astro-ph/0302583) claim white dwarf pairs can be strong radio sources! • 2.9 mJy radio source. • 3 found in current sample. • Only 0.1 per deg2 and 10% of these could be radio sources. • Class 2 in the initial data release, but class 4 spectrum! 6dF workshop

More Related