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相关论文: FR II Quasars: Infrared Properties, Star Formation…

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Fundamental differences in the radio properties of red quasars (QSOs), as compared to blue QSOs, have been recently discovered, positioning them as a potential key population in the evolution of galaxies and black holes across cosmic time.…

[Abridged] We study the evolution of the radio spectral index and far-infrared/radio correlation (FRC) across the star-formation rate-stellar masse (i.e. SFR-M*) plane up to z 2. We start from a M*-selected sample of galaxies with reliable…

We study the radio - far-infrared (FIR) correlation in a sample of faint dwarf irregular galaxies using NVSS data for 1.4 GHz radio flux, Spitzer MIPS 70 um data for FIR flux, and GALEX FUV data to estimate the star formation rates (SFR).…

宇宙学与河外天体物理 · 物理学 2014-09-04 Sambit Roychowdhury , Jayaram N. Chengalur

We discuss the relative merits of mid-infrared and X-ray selection of type-2 quasars. We describe the mid-infrared, near-infrared and radio selection criteria used to find a population of redshift z~2 type-2 quasars which we previously…

We performed spectroscopic observations for a large infrared QSO sample with a total of 25 objects. The sample was compiled from the QDOT redshift survey, the 1 Jy ULIRGs survey and a sample obtained by a cross-correlation study of the IRAS…

天体物理学 · 物理学 2009-11-07 X. Z. Zheng , X. Y. Xia , S. Mao , H. Wu , Z. G. Deng

We positionally match sources observed by the Sloan Digital Sky Survey (SDSS), the Two Micron All Sky Survey (2MASS), and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. Practically all 2MASS sources are matched to an SDSS…

Quasars (of type I) are the luminous analogs of type I Seyfert galaxies. Within the framework of unified models of active galaxies, the population of quasars of type II recently discovered with the Sloan Digital Sky Survey are the luminous…

天体物理学 · 物理学 2010-01-22 Dharam Vir Lal , Luis C. Ho

A multiwavelength study of the star forming regions associated with IRAS 19111+1048 and IRAS 19110+1045 has been carried out. These have been simultaneously mapped in two far infrared bands at lambda_eff ~ 130 and 200 micron with ~1'…

天体物理学 · 物理学 2016-08-30 S. Vig , S. K. Ghosh , V. K. Kulkarni , D. K. Ojha , R. P. Verma

Infrared-faint radio sources (IFRSs) are believed to be a rare class of radio-loud active galactic nuclei (RL AGN) characterized by their high radio-to-infrared flux density ratios of up to several thousands. Previous studies have shown…

星系天体物理 · 物理学 2025-02-11 Yihang Zhang , Lulu Fan , Tao An , Jun Yang , Weibin Sun , Haoran Yu , Yunkun Han

We present Herschel far-infrared (FIR) photometry of eleven quasars at redshift z>5 that have previously been detected at 1.2mm. We perform full spectral energy distribution (SED) fits over the wavelength range lambda_rest ~0.1-400mu for…

宇宙学与河外天体物理 · 物理学 2015-06-16 C. Leipski , K. Meisenheimer , F. Walter , M. -A. Besel , H. Dannerbauer , X. Fan , M. Haas , U. Klaas , O. Krause , H. -W. Rix

Mid-infrared (MIR) quasar spectra exhibit a suite of emission features including high ionization coronal lines from the narrow line region (NLR) illuminated by the ionizing continuum, and hot dust features from grains, as well as polycyclic…

星系天体物理 · 物理学 2015-06-18 Allison R. Hill , S. C. Gallagher , R. P. Deo , E. Peeters , Gordon T. Richards

The low-frequency power spectra of the X-ray and radio emission from four microquasars suggest that two distinct modes of energy output are at work: (i) the `coupled' mode in which the X-ray and radio luminosities are closely coupled and…

天体物理学 · 物理学 2009-11-11 Carlo Nipoti , Katherine M. Blundell , James Binney

We compare the near-infrared (NIR) H band photometric and morphological properties of low-redshift (z<0.3) 3CR radio galaxies with samples of BL Lac object and quasar host galaxies, merger remnants, quiescent elliptical galaxies, and…

Dual quasars, two active supermassive black holes at galactic scales, represent crucial objects for studying the impact of galaxy mergers and quasar activity on the star formation rate (SFR) within their host galaxies, particularly at…

We present Gemini integral field spectroscopy and Keck II longslit spectroscopy of the extended emission-line region (EELR) around the quasar 4C 37.43. The velocity structure of the ionized gas is complex and cannot be explained globally by…

天体物理学 · 物理学 2009-06-23 Hai Fu , Alan Stockton

We investigated the properties of a sample of red Quasi-stellar Objects (QSOs) using optical, radio, and infrared data. These QSOs were selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) quasar catalog. We only selected…

星系天体物理 · 物理学 2017-06-16 An-Li Tsai , Chorng-Yuan Hwang

We compare covering factors of circumnuclear dusty obscurers in radio-loud and radio-quiet quasars. The radio-loud quasars are represented by a sample of FR II quasars obtained by cross-matching a catalog of the FR II radio sources selected…

高能天体物理现象 · 物理学 2016-08-16 Maitrayee Gupta , Marek Sikora , Krzysztof Nalewajko

Observations at mid-infrared (4.8-17.65 um) and radio (0.7-1.3 cm) wavelengths are used to constrain the structure of the high-mass star-forming region W3 IRS5 on 0.1'' (200 AU) scales. Two bright mid-infrared sources are detected, as well…

天体物理学 · 物理学 2009-11-10 F. F. S. van der Tak , P. G. Tuthill , W. C. Danchi

The Fe II/Mg II emission line flux ratio in quasar spectra serves as a proxy for the relative Fe to alpha-element abundances in the broad line regions of quasars. Due to the expected different enrichment timescales of the two elements, they…

We explore the relationship between active galactic nuclei and star formation in a sample of 513 optically luminous type 1 quasars up to redshifts of $\sim$4 hosting extremely high star formation rates (SFRs). The quasars are selected to be…