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GALAXIES ON DIET: FEEDBACK SIGNATURES IN RADIO-AGN HOST GALAXIES
Marios Karouzos,임명신,Markos Trichas,Tomogotsu Goto,Matthew Malkan,Angel Ruiz,전이슬,김지훈,이형목,김성진,Nagisa Oi,Hideo Matsuhara,Toshinobu Takagi,Kazumi Murata,Takehiko Wada,Kensuke Wada,심현진,Hitoshi Hanami,STEPH 한국천문학회 2017 天文學論叢 Vol.32 No.1
There exists strong evidence supporting the co-evolution of central supermassive black holesand their host galaxies; however it is still under debate how such a relation comes about and whether itis relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their hostgalaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedbackmay hence be responsible for the eventual quenching of star formation and halting of galaxy growth. Arich multi-wavelength dataset ranging from the X-ray regime (\textit{Chandra}), to far-IR (\textit{Herschel}), and radio(\textit{WSRT}) is available for the North Ecliptic Pole field, most notably surveyed by the \textit{AKARI} infraredspace telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star formationproperties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radiosources below redshift z = 2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadbandSED modelling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while also offering evidence showcasing a link between AGN activity and host galaxy star formation. In particular, we show results supporting a maintenance type of feedback from powerful radio-jets.
ACTIVE GALACTIC NUCLEUS BLACK HOLE MASS ESTIMATES IN THE ERA OF TIME DOMAIN ASTRONOMY
Kelly, Brandon C.,Treu, Tommaso,Malkan, Matthew,Pancoast, Anna,Woo, Jong-Hak IOP Publishing 2013 The Astrophysical journal Vol.779 No.2
<P>We investigate the dependence of the normalization of the high-frequency part of the X-ray and optical power spectral densities (PSDs) on black hole mass for a sample of 39 active galactic nuclei (AGNs) with black hole masses estimated from reverberation mapping or dynamical modeling. We obtained new Swift observations of PG 1426+015, which has the largest estimated black hole mass of the AGNs in our sample. We develop a novel statistical method to estimate the PSD from a light curve of photon counts with arbitrary sampling, eliminating the need to bin a light curve to achieve Gaussian statistics, and we use this technique to estimate the X-ray variability parameters for the faint AGNs in our sample. We find that the normalization of the high-frequency X-ray PSD is inversely proportional to black hole mass. We discuss how to use this scaling relationship to obtain black hole mass estimates from the short timescale X-ray variability amplitude with precision similar to 0.38 dex. The amplitude of optical variability on timescales of days is also anticorrelated with black hole mass, but with larger scatter. Instead, the optical variability amplitude exhibits the strongest anticorrelation with luminosity. We conclude with a discussion of the implications of our results for estimating black hole mass from the amplitude of AGN variability.</P>
Bennert, Vardha N.,Treu, Tommaso,Auger, Matthew W.,Cosens, Maren,Park, Daeseong,Rosen, Rebecca,Harris, Chelsea E.,Malkan, Matthew A.,Woo, Jong-Hak IOP Publishing 2015 The Astrophysical journal Vol.809 No.1
<P>We create a baseline of the black hole (BH) mass (M-BH)-stellar-velocity dispersion (sigma) relation for active galaxies, using a sample of 66 local (0.02 < z < 0.09) Seyfert-1 galaxies, selected from the Sloan Digital Sky Survey (SDSS). Analysis of SDSS images yields AGN luminosities free of host-galaxy contamination, and morphological classification. 51/66 galaxies have spiral morphology. Out of these, 28 bulges have Sersic index n < 2 and are considered candidate pseudo-bulges, with eight being definite pseudo-bulges based on multiple classification criteria met. Only 4/66 galaxies show signs of interaction/merging. High signal-to-noise ratio Keck spectra provide the width of the broad H beta emission line free of Fe II emission and stellar absorption. AGN luminosity and H beta line widths are used to estimate M-BH. The Keck-based spatially resolved kinematics is used to determine stellar-velocity dispersion within the spheroid effective radius (sigma(spat,reff)). We find that sigma can vary on average by up to 40% across definitions commonly used in the literature, emphasizing the importance of using self-consistent definitions in comparisons and evolutionary studies. The M-BH-sigma relation for our Seyfert-1 galaxy sample has the same intercept and scatter as that of reverberation-mapped AGNs as well as that of quiescent galaxies, consistent with the hypothesis that our single epoch M-BH estimator and sample selection function do not introduce significant biases. Barred galaxies, merging galaxies, and those hosting pseudo-bulges do not represent outliers in the M-BH-sigma relation. This is in contrast with previous work, although no firm conclusion can be drawn on this matter due to the small sample size and limited resolution of the SDSS images.</P>
BROAD H<i>β</i>EMISSION-LINE VARIABILITY IN A SAMPLE OF 102 LOCAL ACTIVE GALAXIES
Runco, Jordan N.,Cosens, Maren,Bennert, Vardha N.,Scott, Bryan,Komossa, S.,Malkan, Matthew A.,Lazarova, Mariana S.,Auger, Matthew W.,Treu, Tommaso,Park, Daeseong American Astronomical Society 2016 The Astrophysical journal Vol.821 No.1
<P>A sample of 102 local (0.02 <= z <= 0.1) Seyfert galaxies with black hole masses M-BH > 10(7)M(circle dot) was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M-BH and host galaxy properties. We study profile changes of the broad H beta emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad H beta emission line is of particular interest, not only because it is used to estimate M-BH, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (similar to 66%) of the objects, resulting in a Seyfert-type change for similar to 38% of the objects, likely driven by variable accretion and/or obscuration. The broad H beta line virtually disappears in 3/102 (similar to 3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of H beta line variability in a sample of low-redshift Seyfert galaxies.</P>
Park, Daeseong,Barth, Aaron J.,Woo, Jong-Hak,Malkan, Matthew A.,Treu, Tommaso,Bennert, Vardha N.,Assef, Roberto J.,Pancoast, Anna American Astronomical Society 2017 The Astrophysical journal Vol.839 No.2
<P>We provide an updated calibration of C IV lambda 1549 broad emission line-based single-epoch (SE) black hole (BH) mass estimators for active galactic nuclei (AGNs) using new data for six reverberation-mapped AGNs at redshift z = 0.005-0.028 with BH masses (bolometric luminosities) in the range 10(6.5)-10(7.5) M-circle dot (10(41.7)-10(43.8) erg s(-1)). New rest-frame UV-to-optical spectra covering 1150-5700 angstrom for the six AGNs were obtained with the Hubble Space Telescope (HST). Multicomponent spectral decompositions of the HST spectra were used to measure SE emission-line widths for the C IV, MgII, and H beta lines, as well as continuum luminosities in the spectral region around each line. We combine the new data with similar measurements for a previous archival sample of 25 AGNs to derive the most consistent and accurate calibrations of the C IV-based SE BH mass estimators against the H beta reverberation-based masses, using three different measures of broad-line width: full. width at half maximum (FWHM), line dispersion (sigma line), and mean absolute deviation (MAD). The newly expanded sample at redshift wz = 0.005-0.234 covers a dynamic range in BH mass (bolometric luminosity) of logM(BH)/M-circle dot = 6.5-9.1 (log L-bol/ erg s(-1) = 41.7-46.9), and we derive the new C IV-based mass estimators using a Bayesian linear regression analysis over this range. We generally recommend the use of sigma line or MAD rather than FWHM to obtain a less biased velocity measurement of the C IV emission line, because its narrow-line component contribution is difficult to decompose from the broad-line profile.</P>
THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES
Barth, Aaron J.,Bennert, Vardha N.,Canalizo, Gabriela,Filippenko, Alexei V.,Gates, Elinor L.,Greene, Jenny E.,Li, Weidong,Malkan, Matthew A.,Pancoast, Anna,Sand, David J.,Stern, Daniel,Treu, Tommaso,W IOP Publishing 2015 The Astrophysical journal Supplement series Vol.217 No.2
<P>In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad H beta line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad Ha line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H beta width and luminosity, demonstrating that the broad-line region 'breathes' on short timescales of days to weeks in response to continuum variations. We also find that broad Ha velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad H beta velocity shifted by similar to 250 km s(-1) over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.</P>
Optical – near-infrared catalog for the AKARI north ecliptic pole Deep field
Oi, Nagisa,Matsuhara, Hideo,Murata, Kazumi,Goto, Tomotsugu,Wada, Takehiko,Takagi, Toshinobu,Ohyama, Youichi,Malkan, Matthew,Im, Myungshin,Shim, Hyunjin,Serjeant, Stephen,Pearson, Chris Springer-Verlag 2014 Astronomy and astrophysics Vol.566 No.-