Yoshiki Matsuoka (NAOJ)

赤方偏移 z < 1 におけるSDSSクエーサー母銀河の性質
Yoshiki Matsuoka (NAOJ),
M. A. Strauss, J. E. Greene, T. N. Price, M. S. DiDonato (Princeton)
Y. Shen (Carnegie Obs; KIAA, Peking), L. C. Ho (KIAA, Peking),
D. P. Schneider, M. Sun, J. R. Trump (Penn State),and the SDSS-III collaboration

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

One-page introduction✶ AGNs/quasars are observed in (~10 % of) galaxy cores throughout the Universe.
✶ Almost every bulge harbors a SMBH in the local Universe, and the Soltan argument suggests thatlocal SMBHs have acquired most of the mass through AGN/quasar phases.
✶ Galaxies and SMBHs may or may not co-evolve.
bulge-SMBH correlation (Kormendy+13)

passive fraction of galaxies (Peng+10)

large energetic outﬂows (Rupke+11)

What is AGN/quasar, in the whole story of galaxy evolution?
- In which galaxies do AGNs/quasars occur?
- What impact do AGNs/quasars have on the galaxies?
第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

We focus on unobscured (type-1) quasars
Vanden Berk+01✶ They are “classical” high-luminosity AGNs.
✶ Most, if not all, of previous statistical studies are based on obscured (type-2) quasars
selected with X-ray luminosity or optical narrow lines. These studies are certainly biased
toward dusty systems, perhaps with enhanced star formation. They may also be subject
to scattered AGN light in host galaxies.
✶ If the merger-driven AGN/SF evolution scenario is correct (which may be questionable),unobscured AGNs precede the phase of obscured AGNs.

Merger-driven evolution model (Alexander+12)
第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

Sample and Data
1. Imaging decomposition analysis“Massive star-forming host galaxies of quasars on SDSS stripe 82” (Matsuoka, Strauss, Price, and DiDonato, 2014, ApJ, 780, 162)
✶ Sample: ~1,000 SDSS DR7/DR9 quasars on Stripe 82✶ Data: SDSS co-add images in u, g, r, i, and z (Annis+14)

2. Spectral decomposition analysis“The SDSS reverberation mapping project: post-starburst signatures in quasar host galaxies at z < 1”(Matsuoka, Strauss, Shen, Greene, Ho, Trump, et al. 2015, in prep.)✶ Sample: ~200 SDSS quasars on the SDSS-RM ﬁeld
✶ Data: SDSS-RM stacked spectra originating from the BOSS spectrograph(λ= 3,650 - 10,400 A)

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

1. Imaging decomposition analysis
The majority of SDSS quasars are resolved on the deep stripe 82 images out to z ~ 0.6
g, r, i composite ­PSF model = extended comp.

model sum
PSF model
Sersic model→ ~80 % of the initial sample are successfully
decomposed into nuclear and host components
in at least three of the g, r, i, and z bands.
第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

2. Spectral decomposition analysis

Black: observed
Red: model sum
Blue: quasar power-law (Apl, αpl)
BLR/NLR templates (Aq)
ISM lines (Alines,σlines)
Green: Maraston+11 SSP (tage, Mstar,σstar)→ ~80 % of the initial sample are successfully
decomposed into nuclear and host components

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

Stellar properties● quasar hosts; imaging decomp.
● quasar hosts; spectral decomp.
● COSMOS/UltraVISTA
normal galaxies (0.5 < z < 1)

✶ The quasars are preferentially hosted by massive (> 1010.5 Msun) galaxies.
✶ The hosts are distributed around the transition area between blue and red galaxies, or themassive tip of the blue cloud, corresponding to tSSP ~ 1 Gyr. (This may indicate that quasars are
directly/indirectly related to the quenching of star formation in galaxies.)✶ When compared to normal galaxies with similar masses, quasar fraction increases toward bluercolors.
第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

Stellar properties

onigH

IIreGNA[O II]/[O III] luminosity ratios are
consistent with quasar photoionization→ SFRs are upper limits✶ The quasar hosts fall below the “main sequence” of star-forming galaxies.
✶ The intermediate stellar ages (tSSP ~ 1 Gyr) and relatively low SFRs suggest that the quasar
hosts have experienced an episode of major star formation sometime in the past ~1 Gyr, which
was subsequently quenched.
✶ Link to post-starburst galaxies?

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

Scaling relations

MBH - σstar relation

MBH - Mstar relation✶ There are positive (although weak) MBH - σstar and MBH - Mstar correlations.
✶ While the mean MBH/σstar and MBH/Mstar ratios are consistent with the local values, therelations seem to ﬂatten toward higher redshifts. This is likely due to selection biases (Shen+15),
and no evolution of the scaling relations is favored at z < 1.

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)

Yoshiki Matsuoka (NAOJ)

Summary✶ AGNs/quasars are a key for understanding galaxy and SMBH evolution.
✶ As a complementary eﬀort to the previous studies of obscured AGNs, we are carrying out
a project to explore host galaxies of unobscured quasars in large contemporary surveys.
✶ The results obtained so far indicate that quasars are preferentially hosted by massive
galaxies distributed around the transition area between blue and red galaxies, with relatively
low SFRs. These facts suggest that the hosts have experienced an episode of major starformation sometime in the past ~1 Gyr, which was subsequently quenched.
✶ The present studies will beneﬁt greatly from future powerful imaging and spectroscopic
survey instruments, such as Subaru HSC and PFS.

第二回銀河進化研究会 (Nagoya; Jun 3-5, 2015)