排序方式: 共有65条查询结果,搜索用时 15 毫秒
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Guinevere Kauffmann Timothy M. Heckman Simon D. M. White Stéphane Charlot Christy Tremonti Jarle Brinchmann Gustavo Bruzual Eric W. Peng Mark Seibert Mariangela Bernardi Michael Blanton Jon Brinkmann Francisco Castander Istvan Csábai Masataka Fukugita Zeljko Ivezic Jeffrey A. Munn Robert C. Nichol Nikhil Padmanabhan Aniruddha R. Thakar David H. Weinberg Donald York 《Monthly notices of the Royal Astronomical Society》2003,341(1):33-53
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The host galaxies of active galactic nuclei 总被引:2,自引:0,他引:2
Guinevere Kauffmann Timothy M. Heckman Christy Tremonti Jarle Brinchmann Stéphane Charlot Simon D. M. White Susan E. Ridgway Jon Brinkmann Masataka Fukugita Patrick B. Hall eljko Ivezi Gordon T. Richards Donald P. Schneider 《Monthly notices of the Royal Astronomical Society》2003,346(4):1055-1077
We examine the properties of the host galaxies of 22 623 narrow-line active galactic nuclei (AGN) with 0.02 < z < 0.3 selected from a complete sample of 122 808 galaxies from the Sloan Digital Sky Survey. We focus on the luminosity of the [O iii ]λ5007 emission line as a tracer of the strength of activity in the nucleus. We study how AGN host properties compare with those of normal galaxies and how they depend on L [O iii ]. We find that AGN of all luminosities reside almost exclusively in massive galaxies and have distributions of sizes, stellar surface mass densities and concentrations that are similar to those of ordinary early-type galaxies in our sample. The host galaxies of low-luminosity AGN have stellar populations similar to normal early types. The hosts of high-luminosity AGN have much younger mean stellar ages. The young stars are not preferentially located near the nucleus of the galaxy, but are spread out over scales of at least several kiloparsecs. A significant fraction of high-luminosity AGN have strong Hδ absorption-line equivalent widths, indicating that they experienced a burst of star formation in the recent past. We have also examined the stellar populations of the host galaxies of a sample of broad-line AGN. We conclude that there is no significant difference in stellar content between type 2 Seyfert hosts and quasars (QSOs) with the same [O iii ] luminosity and redshift. This establishes that a young stellar population is a general property of AGN with high [O iii ] luminosities. 相似文献
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M. den Heijer G. I. G. Jzsa J. Kerp P. Serra Th. van der Hulst G. Kauffmann J. Wang F. Bigiel J. Brinchmann D. Carton D. Cormier M.‐L. Huang 《Astronomische Nachrichten》2015,336(3):284-311
We examine the H I kinematics of the “Bluedisk” ensemble of 48 galaxies selected from the Sloan Digital Sky Survey and observed in H I with the Westerbork Synthesis Radio Telescope. The sample consists of 25 galaxies with a high H I mass fraction and a comparatively large control sample comprising 23 galaxies of comparable stellar mass, stellar mass surface density, redshift, and inclination. By studying the H I velocity fields of these galaxies, we investigate whether there are signatures of ongoing gas accretion: i.e. global asymmetries and indications for warping and kinematical lopsidedness. We find no enhanced kinematical asymmetries between the H I‐rich sample and the control sample galaxies, indicating no significant difference in kinematical signatures such as warping and lopsidedness. Furthermore, we find no difference in position angle and systemic velocity offset with respect to the optical between both sub‐samples. We therefore do not find compelling evidence for enhanced global asymmetry of the H I‐excess galaxies ensemble properties in comparison to the control sample galaxies. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Rachel Mandelbaum † Cheng Li Guinevere Kauffmann Simon D. M. White 《Monthly notices of the Royal Astronomical Society》2009,393(2):377-392
We compute two-point correlation functions and measure the shear signal due to galaxy–galaxy lensing for 80 000 optically identified and 5700 radio-loud active galactic nuclei (AGN) from Data Release 4 of the Sloan Digital Sky Survey. Halo occupation models are used to estimate halo masses and satellite fractions for these two types of AGN. The large sample size allows us to separate AGN according to the stellar mass of their host galaxies. We study how the halo masses of optical and radio AGN differ from those of the parent population at fixed M * . Halo masses deduced from clustering and from lensing agree satisfactorily. Radio AGN are found in more massive haloes than optical AGN: in our samples, their mean halo masses are 1.6 × 1013 and 8 × 1011 h −1 M⊙ , respectively. Optical AGN follow the same relation between stellar mass and halo mass as galaxies selected without regard to nuclear properties, but radio-loud AGN deviate significantly from this relation. The dark matter haloes of radio-loud AGN are about twice as massive as those of control galaxies of the same stellar mass. This boost is independent of radio luminosity, and persists even when our analysis is restricted to field galaxies. The large-scale gaseous environment of the galaxy clearly plays a crucial role in producing observable radio emission. The dark matter halo masses that we derive for the AGN in our two samples are in good agreement with recent models in which feedback from radio AGN becomes dominant in haloes where gas cools quasi-statically. 相似文献
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A. Gil de Paz A. Aragón-Salamanca J. Gallego A. Alonso-Herrero J. Zamorano G. Kauffmann 《Monthly notices of the Royal Astronomical Society》2000,316(2):357-373
We present new near-infrared J and K imaging data for 67 galaxies from the Universidad Complutense de Madrid (UCM) survey used in the determination of the SFR density of the local Universe by Gallego et al. This is a sample of local star-forming galaxies with redshift lower than 0.045, and they constitute a representative subsample of the galaxies in the complete UCM survey. From the new data, complemented with our own Gunn- r images and long-slit optical spectroscopy, we have measured integrated K -band luminosities, r − J and J − K colours, and H α luminosities and equivalent widths. Using a maximum likelihood estimator and a complete set of evolutionary synthesis models, these observations allow us to estimate the strength of the current (or most recent) burst of star formation, its age, the star formation rate and the total stellar mass of the galaxies. An average galaxy in the sample has a stellar mass of 5×1010 M⊙ and is undergoing (or has recently completed) a burst of star formation involving about 2 per cent of its total stellar mass. We identify two separate classes of star-forming galaxies in the UCM sample: low-luminosity, high-excitation galaxies (H ii like ) and relatively luminous spiral galaxies (starburst disc- like ). The former show higher specific star formation rates (SFRs per unit mass) and burst strengths, and lower stellar masses than the latter. With regard to their specific star formation rates, the UCM galaxies are intermediate objects between normal quiescent spirals and the most extreme H ii galaxies. 相似文献
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