A simple model for quasar density evolution

It is widely agreed upon that AGN and Quasars are driven by gas accretion onto a supermassive black hole. The origin of the latter however still remains an open question. In this work we present the results of an extremely simple cosmological model combined with an evolutionary scenario in which both the formation of the black hole as well as the gas accretion onto it are triggered by major mergers of gas-rich galaxies. Despite its very generous approximations our model reproduces the quasar density evolution in remarkable agreement with observations.Comment: 3 pages, 2 figures, to appear in the proceedings of "Relativistic Astrophysics and Cosmology - Einstein's Legacy" (Eds.: B. Aschenbach, V. Burwitz, G. Hasinger, and B. Leibundgut), 7 - 11 November 2005, Munich, Bavaria, German

The 2dF QSO Redshift Survey - XII. The spectroscopic catalogue and luminosity function

We present the final catalogue of the 2dF QSO Redshift Survey (2QZ), based on Anglo-Australian Telescope 2dF spectroscopic observations of 44 576 colour-selected (ubJr) objects with 18.2

The 2dF QSO Redshift Survey - IV. The QSO power spectrum from the 10k catalogue

We present a power spectrum analysis of the 10k catalogue from the 2dF QSO Redshift Survey. Although the Survey currently has a patchy angular selection function, we use the Virgo Consortium's Hubble Volume simulation to demonstrate that we are able to make a useful first measurement of the power spectrum over a wide range of scales. We compare the redshift-space power spectra of QSOs with those measured for galaxies and Abell clusters at low redshift and find that they show similar shapes in their overlap range, , with . The amplitude of the QSO power spectrum at is almost comparable to that of galaxies at the present day if and (the Λ cosmology), and a factor of ≈ 3 lower if (the EdS cosmology) is assumed. The amplitude of the QSO power spectrum is a factor of ≈ 10 lower than that measured for Abell clusters at the present day. At larger scales, the QSO power spectra continue to rise robustly to ≈ 400 h1 Mpc, implying more power at large scales than in the APM galaxy power spectrum measured by Baugh & Efstathiou. We split the QSO sample into two redshift bins and find little evolution in the amplitude of the power spectrum, consistent with the result for the QSO correlation function. In models with this represents evidence for a QSO-mass bias that evolves as a function of time. We compare the QSO power spectra with cold dark matter (CDM) models to obtain a constraint on the shape parameter, Γ. For two choices of cosmology , and , , we find that the best-fitting model has . In addition, we have shown that a power spectrum analysis of the Hubble Volume ΛCDM mock QSO catalogues with as input produces a result that is statistically consistent with the data. The analysis of the mock catalogues also indicates that the above results for Γ are unlikely to be dominated by systematic effects, owing to the current catalogue window. We conclude that the form of the QSO power spectrum shows large-scale power significantly in excess of the standard CDM prediction, similar to that seen in local galaxy surveys at intermediate scales

The 2dF QSO Redshift Survey - XIV. Structure and evolution from the two-point correlation function

In this paper we present a clustering analysis of quasi-stellar objects (QSOs) using over 20000 objects from the final catalogue of the 2dF QSO Redshift Survey (2QZ), measuring the redshift-space two-point correlation function, ξ(s). When averaged over the redshift range 0.3 < z < 2.2 we find that ξ(s) is flat on small scales, steepening on scales above ~25h-1 Mpc. In a WMAP/2dF cosmology (Ωm= 0.27, ΩΛ= 0.73) we find a best-fitting power law with s0= 5.48+0.42-0.48h-1 Mpc and γ= 1.20 +/- 0.10 on scales s= 1 to 25h-1 Mpc. We demonstrate that non-linear redshift-space distortions have a significant effect on the QSO ξ(s) at scales less than ~10h-1 Mpc. A cold dark matter model assuming WMAP/2dF cosmological parameters is a good description of the QSO ξ(s) after accounting for non-linear clustering and redshift-space distortions, and allowing for a linear bias at the mean redshift of bQ(z= 1.35) = 2.02 +/- 0.07. We subdivide the 2QZ into 10 redshift intervals with effective redshifts from z= 0.53 to 2.48. We find a significant increase in clustering amplitude at high redshift in the WMAP/2dF cosmology. The QSO clustering amplitude increases with redshift such that the integrated correlation function, , within 20h-1 Mpc is and . We derive the QSO bias and find it to be a strong function of redshift with bQ(z= 0.53) = 1.13 +/- 0.18 and bQ(z= 2.48) = 4.24 +/- 0.53. We use these bias values to derive the mean dark matter halo (DMH) mass occupied by the QSOs. At all redshifts 2QZ QSOs inhabit approximately the same mass DMHs with MDH= (3.0 +/- 1.6) × 1012h-1 Msolar, which is close to the characteristic mass in the Press-Schechter mass function, M*, at z= 0. These results imply that L*Q QSOs at z~ 0 should be largely unbiased. If the relation between black hole (BH) mass and MDH or host velocity dispersion does not evolve, then we find that the accretion efficiency (L/LEdd) for L*Q QSOs is approximately constant with redshift. Thus the fading of the QSO population from z~ 2 to ~0 appears to be due to less massive BHs being active at low redshift. We apply different methods to estimate, tQ, the active lifetime of QSOs and constrain tQ to be in the range 4 × 106-6 × 108 yr at z~ 2. We test for any luminosity dependence of QSO clustering by measuring ξ(s) as a function of apparent magnitude (equivalent to luminosity relative to L*Q). However, we find no significant evidence of luminosity-dependent clustering from this data set

The 2dF QSO Redshift Survey - V. The 10k catalogue

We present a catalogue comprising over 10 000 QSOs covering an effective area of 289.6 deg2, based on spectroscopic observations with the 2-degree Field (2dF) instrument at the Anglo-Australian Telescope. This catalogue forms the first release of the 2dF QSO Redshift Survey. QSO candidates with 18.2

Quasars and their host galaxies

This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass estimates for quasars, and our confidence in them, have improved significantly, allowing a start on relating quasar properties such as radio jet power to fundamental parameters of the quasar such as black hole mass and accretion rate. Quasar host galaxy studies have allowed us to find and characterize the host galaxies of quasars to z>2. Despite these developments, many questions remain unresolved, in particular the origin of the close relationship between black hole mass and galaxy bulge mass/velocity dispersion seen in local galaxies.Comment: Review article, to appear in Astrophysics Update

The Close AGN Reference Survey (CARS) A massive multi-phase outflow impacting the edge-on galaxy HE 1353-1917

Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society.Context. Galaxy-wide outflows driven by star formation and/or an active galactic nucleus (AGN) are thought to play a crucial rule in the evolution of galaxies and the metal enrichment of the inter-galactic medium. Direct measurements of these processes are still scarce and new observations are needed to reveal the nature of outflows in the majority of the galaxy population. Aims. We combine extensive, spatially-resolved, multi-wavelength observations, taken as part of the Close AGN Reference Survey (CARS), for the edge-on disc galaxy HE 1353-1917 in order to characterise the impact of the AGN on its host galaxy via outflows and radiation. Methods. Multi-color broad-band photometry was combined with spatially-resolved optical, near-infrared (NIR) and sub-mm and radio observations taken with the Multi-Unit Spectroscopy Explorer (MUSE), the Near-infrared Integral Field Spectrometer (NIFS), the Atacama Large Millimeter Array (ALMA), and the Karl G. Jansky Very Large Array (VLA) to map the physical properties and kinematics of the multi-phase interstellar medium. Results. We detect a biconical extended narrow-line region ionised by the luminous AGN orientated nearly parallel to the galaxy disc, extending out to at least 25 kpc. The extra-planar gas originates from galactic fountains initiated by star formation processes in the disc, rather than an AGN outflow, as shown by the kinematics and the metallicity of the gas. Nevertheless, a fast, multi-phase, AGN-driven outflow with speeds up to 1000 km s(-1) is detected close to the nucleus at 1 kpc distance. A radio jet, in connection with the AGN radiation field, is likely responsible for driving the outflow as confirmed by the energetics and the spatial alignment of the jet and multi-phase outflow. Evidence for negative AGN feedback suppressing the star formation rate (SFR) is mild and restricted to the central kpc. But while any SFR suppression must have happened recently, the outflow has the potential to greatly impact the future evolution of the galaxy disc due to its geometrical orientation. Conclusions.. Our observations reveal that low-power radio jets can play a major role in driving fast, multi-phase, galaxy-scale outflows even in radio-quiet AGN. Since the outflow energetics for HE 1353-1917 are consistent with literature, scaling relation of AGN-driven outflows the contribution of radio jets as the driving mechanisms still needs to be systematically explored.© B. Husemann et al. 2019We thank the referee for providing very valuable comments, which significantly improved the quality of the manuscript. MK acknowledges support from DLR grant 50OR1802. GRT acknowledges support from the NASA through Einstein Postdoctoral Fellowship Award Number PF-150128, issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. MG is supported by the Lyman Spitzer Jr. Fellowship (Princeton University) and by NASA Chandra grants GO7-18121X/GO8-19104X. SMC acknowledges support from the Australian Research Council (DP190102714). We thank Alex Markowitz for helpful discussions on the RGS data in the context of warm absorbers. The work of SAB, CPO and MS was supported by a generous grant from the Natural Sciences and Engineering Research Council of Canada. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under ESO programme 095. B-0015(A). Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnologia e Innovacion Productiva (Argentina), Ministerio da Ciencia, Tecnologia e Inovacao (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC) do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut fur Astronomie Heidelberg and the Instituto de Astrofiica de Andaluci (CSIC). This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00952. S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This work is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. The VLA is operated by the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. This work is based in part on observations made with the Galaxy Evolution Explorer (GALEX). GALEX is a NASA Small Explorer, whose mission was developed in cooperation with the Centre National d'Etudes Spatiales (CNES) of France and the Korean Ministry of Science and Technology. GALEX is operated for NASA by the California Institute of Technology under NASA contract NAS5-98034

An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles

The extreme solar and SEP event of 20 January 2005 is analyzed from two perspectives. Firstly, we study features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly, we relate our results to a long-standing controversy on the origin of SEPs arriving at Earth, i.e., acceleration in flares, or shocks ahead of CMEs. All emissions from microwaves up to 2.22 MeV line gamma-rays during the main flare phase originated within a compact structure located just above sunspot umbrae. A huge radio burst with a frequency maximum at 30 GHz was observed, indicating the presence of a large number of energetic electrons in strong magnetic fields. Thus, protons and electrons responsible for flare emissions during its main phase were accelerated within the magnetic field of the active region. The leading, impulsive parts of the GLE, and highest-energy gamma-rays identified with pi^0-decay emission, are similar and correspond in time. The origin of the pi^0-decay gamma-rays is argued to be the same as that of lower energy emissions. We estimate the sky-plane speed of the CME to be 2000-2600 km/s, i.e., high, but of the same order as preceding non-GLE-related CMEs from the same active region. Hence, the flare itself rather than the CME appears to determine the extreme nature of this event. We conclude that the acceleration, at least, to sub-relativistic energies, of electrons and protons, responsible for both the flare emissions and the leading spike of SEP/GLE by 07 UT, are likely to have occurred simultaneously within the flare region. We do not rule out a probable contribution from particles accelerated in the CME-driven shock for the leading GLE spike, which seemed to dominate later on.Comment: 34 pages, 14 Postscript figures. Solar Physics, accepted. A typo corrected. The original publication is available at http://www.springerlink.co

The SAMI Galaxy Survey: Spatially resolving the environmental quenching of star formation in GAMA galaxies

We use data from the Sydney-AAO Multi-Object Integral Field Spectrograph (SAMI) Galaxy Survey and the Galaxy And Mass Assembly (GAMA) survey to investigate the spatially-resolved signatures of the environmental quenching of star formation in galaxies. Using dust-corrected measurements of the distribution of Hα emission we measure the radial profiles of star formation in a sample of 201 star-forming galaxies covering three orders of magnitude in stellar mass (M∗M∗; 108.1-1010.95 M⊙) and in 5th nearest neighbour local environment density (Σ5; 10−1.3- 102.1 Mpc−2). We show that star formation rate gradients in galaxies are steeper in dense (log10(Σ5/Mpc2) > 0.5) environments by 0.58 ± 0.29 dex re−1 in galaxies with stellar masses in the range 1010 1.0). These lines of evidence strongly suggest that with increasing local environment density the star formation in galaxies is suppressed, and that this starts in their outskirts such that quenching occurs in an outside-in fashion in dense environments and is not instantaneous

Observing Supermassive Black Holes across cosmic time: from phenomenology to physics

In the last decade, a combination of high sensitivity, high spatial resolution observations and of coordinated multi-wavelength surveys has revolutionized our view of extra-galactic black hole (BH) astrophysics. We now know that supermassive black holes reside in the nuclei of almost every galaxy, grow over cosmological times by accreting matter, interact and merge with each other, and in the process liberate enormous amounts of energy that influence dramatically the evolution of the surrounding gas and stars, providing a powerful self-regulatory mechanism for galaxy formation. The different energetic phenomena associated to growing black holes and Active Galactic Nuclei (AGN), their cosmological evolution and the observational techniques used to unveil them, are the subject of this chapter. In particular, I will focus my attention on the connection between the theory of high-energy astrophysical processes giving rise to the observed emission in AGN, the observable imprints they leave at different wavelengths, and the methods used to uncover them in a statistically robust way. I will show how such a combined effort of theorists and observers have led us to unveil most of the SMBH growth over a large fraction of the age of the Universe, but that nagging uncertainties remain, preventing us from fully understating the exact role of black holes in the complex process of galaxy and large-scale structure formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and Treves A. (Eds), 2015, Springer International Publishing AG, Cha