Chandra s view of local op.cally dull X ray bright galaxies. Daryl Haggard CIERA Fellow

Transcription

1 Chandra s view of local op.cally dull X ray bright galaxies Daryl Haggard CIERA Fellow

2 Collaborators James Madison University Anca Constan6n Harvard Smithsonian Center for Astrophysics ROSAT Paul J. Green Dong Woo Kim University of Washington ScoE F. Anderson University of Birmingham SDSS Ewan O Sullivan Evanston Township High School Talia Weiss XBONGS, Fall 2011 Chandra Daryl Haggard, Northwestern/CIERA 2

3 X ray Bright, Op6cally Normal Galaxies XBONG (a.k.a. op6cally dull X ray bright gals) Substan6al (AGN like) X ray luminosity No narrow or broad op6cal emission lines e.g., Elvis et al XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 3

4 X ray Bright, Op6cally Normal Galaxies Observa6ons alterna6vely aeributed to: XBONG (a.k.a. op6cally dull X ray bright gals) dilu6on, obscura6on, inefficient accre6on, Substan6al (AGN like) X ray luminosity variability, extended hot gas No narrow or broad op6cal emission lines e.g., Elvis et al Low z sample to dis6nguish between scenarios XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 4

5 X ray Bright, Op6cally Normal Galaxies Why no AGN like op6cal emission lines? Dilu+on: AGN emission diluted by host starlight Moran et al. 2002; Caccianiga et al. 2007; Trump et al Obscura+on: Both broad & narrow line regions Comastri et al. 2002; Rigby et al obscured Inefficient Accre+on: RIAFs with truncated disks Yuan & Narayan et al. 2004; Trump et al (liele op6cal/uv) Variability: data not coeval; 6dal disrup6ons Komassa et al. 2004; Gezari et al Extended hot gas: poor or fossil galaxy groups Jones et al. 2003; Georgantopoulos & Georgakakis et al XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 5

6 Low z XBONGs A low redshil (z < 0.37) sample enables: High X ray S/N spectral constraints spa6al modeling Hα in the op6cal spectrum Deep, mul6wavlength op6cal data environment studies (via photometric redshils) spectroscopic follow up Host galaxy morphology ROSAT + Chandra enables variability analysis Unique, high resolu6on look at a rare popula6on XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 6

7 Low z XBONGs A low redshil (z < 0.37) sample enables: High X ray S/N spectral constraints spa6al modeling Hα in the op6cal spectrum Deep, mul6wavlength op6cal data environment studies (via photometric redshils) spectroscopic follow up Host galaxy morphology ROSAT + Chandra enables variability analysis Unique, high resolu6on look at a rare popula6on XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 7

8 Name (SDSS) Low z XBONG Sample 8 local targets selected for Chandra follow up: r (mag) z RASS (cnts/s) log L x (erg/s) match conf (%) J J J J J J J J XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 8

9 Name (SDSS) Low z XBONG Sample SDSS spec r (mag) z ~ 0.3 z RASS (cnts/s) RASS bright log L x (erg/s) match conf (%) J J J J J J J J XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 9

10 No Measurable Clustering Associa6on with groups and clusters possible RASS sources not reliably extended un6l 1, but 97% of sources above 20 extent excluded Neighbors have SDSS photometric redshils Bohringer et al Eliminate catalog matches RASS XBONG cands no more clustered than non RASS passives XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 10

11 ksec Chandra ACIS S exposures 4 5 of 8 appear extended XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 11

12 Extended X ray Emission XBONGS, Fall

13 SDSS J XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 13

14 SDSS J D King Model: S(R) = S 0 [1+(r/r c ) 2 ] 3β+½ r c = 8.9pix = 4.38 ~ 18kpc β = 0.48 XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 14

15 SDSS J z = nh = 2.58x10 20 atm/cm 2 MEKAL thermal plasma model fit to X ray spectrum ~1400 counts kt = 5.17±1.0 kev Abund = 0.64±0.4 solar f 0.3 8keV = 6.15 x erg s 1 cm 2 L 0.3 8keV = 1.47 x erg s 1 XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 15

16 L x T x Rela6on for Clusters/Groups SDSS J1200 Miller et al Miller et al XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 16

17 Extended X ray Emission kt = 4.6 kev log (L x ) = kt = 5.2 kev log (L x ) = kt = 8.7 kev log (L x ) = 44.5 point source: cnts = 60; Γ =2.2 log (L x ) = kt = 1.4 kev log (L x ) = kt = 6.2 kev log (L x ) = 44.0 XBONGS, Fall

18 L x T x Rela6on for Clusters/Groups Miller et al Miller et al XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 18

19 Marginal Detec6ons RIAF or X ray Variability possible. Host dilu6on unlikely. XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 19

20 Summary 8 low z (< 0.37) XBONGs observed with Chandra: 4 to 5 extended (!) in the X ray Radial profiles and X ray spectra consistent with (fossil) group or X ray cluster interpreta6on 2 to 3 show no strong X ray emission X ray variability? (possible 6dal disrup6on events) Promising new selec6on technique for op6cally poor, low z groups/clusters Follow up: Spectroscopic confirma6on of group/cluster environment High quality (XMM/Astro H) spectra to constrain T x XBONGS, Fall 2011 Daryl Haggard, Northwestern/CIERA 20

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