Related papers: What makes a galaxy radio-loud?
We investigate the luminosity evolution of the host galaxies of radio-loud AGN through Hubble Space Telescope imaging of 72 BL Lac objects, including new STIS imaging of nine z > 0.6 BL Lacs. With their intrinsically low accretion rates and…
The radio-X-ray slope in the fundamental plane of radio-loud active galactic nuclei (AGNs) is found to be steeper compared with that of radio-quiet AGNs in previous works. In this work, we reinvestigate the fundamental plane in radio-loud…
A toy model for jet powers and radio loudness of active galactic nuclei (AGNs) is proposed based on the coexistence of the Blandford-Znajek (BZ) and magnetic coupling (MC) processes (CEBZMC) in black hole (BH) accretion disc. It turns out…
Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation…
Since the discovery of Quasi-stellar Objects (QSOs), also known as quasars, they have been traditionally subdivided as radio-loud and radio-quiet sources. Whether such division is a misleading effect from a highly heterogeneous single…
We study the Extended Chandra Deep Field South (E-CDFS) Very Large Array sample, which reaches a flux density limit at 1.4 GHz of 32.5 microJy at the field centre and redshift ~ 4, and covers ~ 0.3 deg^2. Number counts are presented for the…
(Abridged) The prevalence of radio-loud AGN activity in present-day massive halos is determined using a sample of 625 nearby groups and clusters from the SDSS. Brightest group and cluster galaxies (BCGs) are more likely to host a radio-loud…
Basing our analysis on ROGUE I, a catalog of over 32,000 radio sources associated with optical galaxies, we provide two diagnostics to select the galaxies where the radio emission is due to an active galactic nucleus (AGN). Each of these…
Galaxy evolution and extragalactic astronomy research depend on an understanding of the interactions between active galactic nuclei (AGN) and their host galaxies. We investigate the relationships between X-ray luminosity (Lx), star…
A catalogue of 14453 radio-loud AGN with 1.4 GHz fluxes above 3.5 mJy in the redshift range 0.4<z<0.8, has been constructed from the cross-correlation of the NVSS and FIRST radio surveys with the MegaZ-LRG catalogue of luminous red galaxies…
It has been argued for years that the accretion mode changes from bright active galactic nuclei (AGNs) to low-luminosity AGNs (LLAGNs) at a rough dividing point of bolometric Eddington ratio $\lambda \sim 10^{-2}$. In this work, we…
Young radio galaxies (YRGs) provide an ideal laboratory to explore the connection between accretion disk and radio jet thanks to their recent jet formation. We investigate the relationship between the emission-line properties, the black…
We briefly review BeppoSAX observations of X-ray bright radio-galaxies. Their X-ray spectra are quite varied, and perhaps surprisingly, any similarity between radio-loud AGN and Seyfert galaxies is the exception rather than the rule. When…
We have studied the dependence of the AGN nuclear radio (1.4 GHz) luminosity on both the AGN 2-10 keV X-ray and the host-galaxy K-band luminosity. A complete sample of 1268 X-ray selected AGN (both type 1 and type 2) has been used, which is…
(Abridged) We present the results from new 15 ks Chandra-ACIS and 4.9 GHz Very Large Array observations of 13 galaxies hosting low luminosity AGN. This completes the multiwavelength study of a sample of 51 nearby early-type galaxies…
We have studied the relationship between the AGN radio-loudness and the mass of the central black-hole by using the ~190 type 1 AGN selected in the XMM-Newton Bright Survey (XBS). We find that radio-loud AGNs are much more frequent at high…
We present a study of spectral properties of galaxies in underdense large-scale structures, voids. Our void galaxy sample (75,939 galaxies) is selected from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) with $\rm z < 0.107$. We…
We investigate the 1.4 GHz radio properties of 92 nearby (z<0.05) ultra hard X-ray selected Active Galactic Nuclei (AGN) from the Swift Burst Alert Telescope (BAT) sample. Through the ultra hard X-ray selection we minimise the biases…
We present results from a survey of 70 radio galaxies (RGs) at redshifts 1<z<5.2 using the PACS and SPIRE on-board Herschel. Combined with existing mid-IR photometry from Spitzer and observations obtained with LABOCA, the SEDs of galaxies…
The supermassive black holes ($M_{\rm BH} \sim 10^{6}$$-$$10^{10}~M_\odot$) that power luminous active galactic nuclei (AGNs), i.e., quasars, generally show a correlation between thermal disk emission in the ultraviolet (UV) and coronal…