A Peculiar Radio-Loud Narrow-Line Seyfert 1

A Peculiar Radio-Loud Narrow-Line Seyfert 1

A Peculiar Radio-Loud
Narrow-Line Seyfert 1
< 1 night
Tomoki Morokuma (University of Tokyo)
M. Tanaka et al. 2014, ApJ Letters, 793, L26
(radio-loud) narrow-line Seyfert 1
‣ “narrow” broad emission lines
‣ <2000 km/s
‣ small supermassive black holes
‣ 105-8 Msun SMBH
‣ rare population
‣ 15% of broad-line AGN (SDSS)
‣ high Eddington ratio = high accretion rate
‣ Lbol/LEdd>0.1
‣ growing SMBH
‣ weak [OIII]: [OIII]/Hbeta<3
‣ small amplitude of variability(?)
‣ radio-quiet
‣ Only ~7% of NLS1 are radio-loud (R>10).
SDSS J1100+4420 (KISS14k)
‣ rapid optical “flare” discovered
‣ high-cadence SN survey Kiso Supernova Survey (KISS; TM+2014)
‣ Kiso Schmidt (1.05m) + KWFC (4 deg2 FoV)
‣ supernova shock breakout !?!?!?
Follow-Up Observation (1): Optical w/ Subaru
‣ optical imaging & spectroscopy w/ Subaru/FOCAS (TM+, S14A-164)
‣ “narrow” broad emission lines (MgII, Hbeta) ==> 2x107 Msun SMBH
‣ no changes of power-law indices (spectral slopes)
‣ strong [OIII] emission lines ([OIII]/Hbeta>7)
SDSS J1100+4420 (KISS14k)
‣ “narrow” broad emission lines
‣ <2000 km/s: v(MgII)=2070km/s, v(Hbeta)=1900km/s
‣ smaller supermassive black holes (SMBHs)
‣ 105-8 Msun SMBH: 2x107 Msun SMBH
‣ rare population
‣ 15% of broad-line AGN (SDSS)
‣ high Eddington ratio = high accretion rate (Lbol/LEdd>0.1): Lbol/LEdd~0.3
‣ growing SMBH
‣ weak [OIII]: [OIII]/Hbeta<3: high L([OIII]). [OIII]/Hbeta~7
‣ small amplitude of variability(?): rapid optical “flare”
‣ radio-quiet
‣ Only ~7% of NLS1 are radio-loud (R>10). ‣ radio-loudness R~3000
‣ extended radio emission: ~100 kpc?
‣ SED consistent with previous gamma-loud/radio-loud NLS1s
SED: Archival/new data from radio to gamma-ray
radio
IR/opt X-ray gamma-ray
Fermi/2FGL
Swift
similar SED to gamma-loud NLS1
Follow-Up Observation (2): radio w/ JVN
Japan VLBI Network (JVN)
http://www.astro.sci.yamaguchi-u.ac.jp/jvn/
August 2, 2014 (UT)
8 GHz
Yamaguchi, Hitachi, Usuda
aims
flux measurement (==> monitoring)
spectral shape
morphology
~ 100 mJy (preliminary)
Nature of KISS14k
‣ very radio-loud
‣ short (~hours) time scale variability in optical
‣ constant optical spectral slope during luminosity change
‣ ==> relativistic jet
‣ Extended (~100 kpc) radio structure
‣ SED consistent with other gamma-loud/radio-loud NLS1
‣ (#) Origin of high [OIII] luminosity? extended narrow line region?
‣ (#) faint host?: fainter than -21.5 mag
‣ star-forming, not similar to blazer host galaxies
Follow-Up Observation (3): radio (JVN), IR-optical (OISTER)
multi-wavelength monitoring (over 1 month, Oct-Nov 2014)
Optical and Infrared Synergetic Telescopes for Education and
Research (OISTER): optical & NIR
http://oister.oao.nao.ac.jp
10 institutes (9 universities), 13 telescopes
Japan - South Africa - Chile
Japan VLBI Network (JVN): radio
Summary
‣ We detected a rapid optical flare from a radio-loud NLS1 in our
high-cadence supernova survey KISS. ‣ Optical spectra
‣ “narrow” broad emission line: ‣ v(MgII)=2070km/s, v(Hbeta)=1900km/s
‣ 2x107 Msun SMBH
‣ high [OIII] luminosity: [OIII]/Hbeta~7
‣ origin?
‣ very radio-loud: R~3000
‣ extended (~100 kpc) emission
‣ Simultaneous observations over wide wavelength range are required. ‣ coordinated observation of OISTER (optical) & JVN (radio)
‣ High-resolution interferometric observation will be done soon.