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H. Zhou, T.-G. Wang, H. Lu, X. Dong J. Wang, Y. Lu University of Science & Technology of China

Systematic study of a large sample of NLS1 galaxies from SDSS — first results. Weimin Yuan Yunnan Observatory/NAOC, CAS, Kunming, China. H. Zhou, T.-G. Wang, H. Lu, X. Dong J. Wang, Y. Lu University of Science & Technology of China Hefei.

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H. Zhou, T.-G. Wang, H. Lu, X. Dong J. Wang, Y. Lu University of Science & Technology of China

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  1. Systematic study of a large sample of NLS1 galaxies from SDSS — first results Weimin Yuan Yunnan Observatory/NAOC, CAS, Kunming, China H. Zhou, T.-G. Wang, H. Lu, X. Dong J. Wang, Y. Lu University of Science & Technology of China Hefei H. Zhou, T.-G. Wang, W. Yuan, et al. 2006, ApJS, 166, 128

  2. Narrow Line Seyfert 1 galaxies • narrow Balmer linesFWHM(Hβ)<2000km/s • [OIII]/ Hβ small (<3) • strong FeII • soft X-ray: steep spectrum,rapid variability • outflows ([OIII] and CIV)…) • extreme region in the eigenvector 1 space •  small BH mass and high L/LEdd • useful to constrain AGN models

  3. Controversial and unexplored issues ~ 400 NLS1s known before our sample (incl. e.g., the SDSS EDR NLS1 sample of ~150, Williams et al. 2002) • broad band SED • black hole mass determination, MBH - sigma relation • NLS1s with flat soft X-ray spectra • [OIII] strength, NLR, outflows • host galaxies • type 2 counterparts • optical variability • radio-loud NLS1, radio-emission, jets? • accretion models • evolution A larger and homogeneous NLS1 sample is needed

  4. Analysis of SDSS spectra Search from SDSS spectroscopic targets as galaxies and QSO Spectral decomposition of host galaxy starlight and nuclear (continuum + emission lines), using our EL-ICA algorithm (Ensemble Learning – Independent Component Analysis) Using 6 IC synthesized galaxy templates built up from the SSP spectral library of Bruzual & Charlot 2003 Lu et al. 2006, AJ, 131, 790  stellar V dispersion also obtained

  5. Spectral line fittingbroad and narrow line de-blending Hαregion Hβregion

  6. NLS1 sample from the SDSS DR3 The sample was drawn from ~387,483 galaxies and QSO in the SDSS DR3 (z<0.8) Selection criteria: Hα or Hβ detected at >10 σ significance level FWHM < 2200 km/s The sample: 2011 NLS1 1885 NLS1 (FWHM<2000 km/s) <7% have radio detection (c.f. 10% for BL AGN) NLS1 fraction: 15% in radio-quiet & radio-intermediate AGN (R<1) 10% in moderate radio-loud AGN (1<R<2) <5% in very radio-loud AGN (R>2) The FeII emission in NLS1s is ~twice stronger than normal BL AGN

  7. note The conventional NLS1 definition may include some AGNs with IMBH mass Objects with MBH <~ 106 M⊙ See poster # 268 for our IMBH (<~ 106 M⊙ ) AGN sample

  8. Line EW – luminosity relation --- (inverse) Baldwin effect EW Hβ EW FeII Hβluminosity λL λluminosity at 5100Ǻ

  9. Soft X-ray Slope vs. FWHM (Balmer) ROSAT photon index ROSAT photon index FWHM Hβ(km/s) FWHM Hα(km/s) Turnover line-width ~ 1000km/s

  10. Narrow line region No difference between NLS1 and normal BL AGN

  11. Black hole mass – stellar velocity dispersion relation MBH: estimated from line-width and luminosity (e.g. kaspi et al. 2000, Mclure & Jarvis 2002, Dietrich & Hamann) σ: measured from fitting the nuclear starlight spectra of host galaxies by the galaxy-nuclear spectral decomposition algorithm Traimaine etal. 2002 Black hole mass (M⊙) stellar velocity dispersion(km/s)

  12. Black hole mass – stellar velocity dispersion relation Possible contamination of σby the rotation galactic disk? Use only nearby galaxies with face-on disks or their SDSS fiber aperture 3” dominated by galactic bulges Traimaine etal. 2002 Black hole mass (M⊙) NLS1 are underage AGN in which the growth of the SMBH lags the formation of the bulge stellar velocity dispersion(km/s) e.g. Mathur et al. 2001, Grupe & Mathur 2004, Biao & Zhao 2004, , Botte et al. 2004, Wang & Lu, Wandel 2002, 2004, ……)

  13. Providing to the AGN community with the largest NLS1 sample The frequency of finding NLS1s depends strongly on optical luminosity and radio-loudness Turnover of the trend of soft X-ray Slope vs. FWHM (Balmer) Inverse Baldwin effect seen in Hbeta and FeII NLR in NLS1s is not different from that of BLS1s  finding NLS2 is challenging NLS1s are underage AGN in which the growth of the SMBH lags the formation of the bulge summary

  14. Current work • Search for optical variability • ~150 covered in the SDSS SN survey (preliminary resultssee poster #280 Y. Ai et al.) • optical monitoring • X-ray data analysis (XMM, ROSAT, etc.) a sample of ~40 objects with XMM data

  15. XMM-Newton spectral fits one power law one power law: 10/22 PL + soft x-ray excess: 12/22 No significant Fe K line Other models, e.g. p-free model (S. Mineshige’s talk) Broken power law

  16. Example of spectral fits to XMM data L. Fan, et al. in prep.

  17. Results of spectral fits for the XMM sub-sample with enough photon counts (~30 objects) L. Fan, et al. in prep.

  18. distribution of the photon index of the underlying power-law

  19. Current work and future plan • much detailed statistical analysis • Fraction of NLS1 w.r.t. luminosity, z, etc. • …… • broad band properties and SED • UV (Galex) • Host galaxy morphology and stellar contents • new radio/X-ray observations • photometric/spectroscopic monitor, variability study • possible black hole mass measurement by reverberation mapping • Cosmic evolution: NLS1 sample at higher redshifts using the MgII line

  20. A NLS1-blazar composite J0324+3410 HST residual image one-armed spiral SDSS spectrum: typical of NLS1

  21. A NLS1-blazar composite SDSS J0324+3410 Non-thermal continuum SED resembles Mrk 421 TeV γ-ray detected (3 σ) by Whipple (Falcone 0’4) Intra-night large amplitude variability X-ray fast variability seen by Swift myth ? NLS1: high accretion rate HPB: low accretion rate HPB blazar Zhou, Wang, Yuan et al. 2006 ApJL submitted

  22. AGN with IMBH in the dwarf galaxy J1605+1748MBH~ 6 x104 M⊙ (Kaspi et al. 2005) 2.5 x105 M⊙ (Bentz et al.2006) poster # 268 Dong, Wang, Yuan, et al., ApJ submitted, astro-ph/0610145

  23. IMBH in the dwarf galaxy J1605+1748 host galaxy MR~ -17.8

  24. NLS1s from SDSS(3) Frequency of finding NLS1s: strongly dependent on optical luminosity

  25. The Fe II emission strength R4570 = Fe II (λ4434-4684) / Hβ The FeII emission in NLS1s is ~twice stronger than normal BL AGN

  26. Radio-loudness

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