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author = "Alexander, D M"

Found 162 documents, displaying page 1 of 17

The X-ray-Infrared/Submillimetre Connection and the Legacy Era of Cosmology

Author(s) : Alexander, D. M.
Description : We review some recent results on the identification and characterisation of Active Galactic Nuclei (AGN) obtained by cross correlating X-ray surveys with infrared and submillimetre surveys. We also look toward the scientific gains that could be achieved from an XMM-Newton survey of the medium-deep...
Repository : arXiv
Language(s) : Undetermined

Where do z~2 Submillimeter-Emitting Galaxies Lie On the Black-Hole-Spheroid Mass Plane?

Author(s) : Alexander, D. M.
Description : Submillimeter-emitting galaxies (SMGs) are z~2 bolometrically luminous systems hosting energetic starburst and AGN activity. SMGs may represent a rapid growth phase that every massive galaxy undergoes before lying on the well-established black-hole-spheroid mass relationship in the local Universe....
Repository : arXiv
Language(s) : Undetermined

Identifying the Obscured Black-Hole Growth Phase of Distant Massive Galaxies

Author(s) : Alexander, D. M.
Description : It is well established that a dominant phase in the growth of massive galaxies occurred at high redshift and was heavily obscured by gas and dust. Many studies have explored the stellar growth of massive galaxies but few have combined these constraints with the growth of the supermassive black hol...
Repository : arXiv
Language(s) : Undetermined

On the Seyfert 2 warm and cool infrared dichotomy

Author(s) : Alexander, D. M.
Description : An optical spectropolarimetric study has shown that the detectability of polarised broad H-alpha in Seyfert 2 galaxies is correlated to the IRAS f60/f25 flux ratio where only those Seyfert 2s with "warm" IRAS colours show polarised broad line emission. It was suggested that those Seyfert 2s with "...
Repository : arXiv
Language(s) : Undetermined

The Unified model and the Seyfert 2 infrared dichotomy

Author(s) : Alexander, D. M.
Description : An optical spectropolarimetric study has shown that the detectability of polarised broad H-alpha in Seyfert 2 galaxies is correlated to the IRAS f60/f25 flux ratio where only those Seyfert 2s with "warm" IRAS colours show polarised broad line emission. It was suggested that those Seyfert 2s with "...
Repository : arXiv
Language(s) : Undetermined

The Quest for a Complete Census of AGN Activity

Author(s) : Alexander, D. M.
Description : Deep X-ray surveys provide the most efficient identification of Active Galactic Nuclei (AGN) activity. However, recent evidence has indicated that the current <10 keV surveys do not detect the most heavily obscured AGNs. Here we explore whether the X-ray undetected AGN population can be identified...
Repository : arXiv
Language(s) : Undetermined

Weighing Black Holes in high-z SCUBA Galaxies

Author(s) : Alexander, D. M.
Description : Deep SCUBA surveys have uncovered a population of dust-enshrouded star-forming galaxies at z~2. Using the ultra-deep 2 Ms Chandra Deep Field-North survey we recently showed that a large fraction of these systems are also undergoing intense black-hole growth. Here we provide further constraints on ...
Repository : arXiv
Language(s) : Undetermined

A local infrared perspective to deeper ISO surveys

Description : We present new techniques to produce IRAS 12 micron samples of galaxies and stars. We show that previous IRAS 12 micron samples are incompatible for detailed comparison with ISO surveys and review their problems. We provide a stellar infrared diagnostic diagram to distinguish galaxies from stars w...
Repository : arXiv
Language(s) : Undetermined

Supermassive black-hole growth over cosmic time: Active galaxy demography, physics, and ecology from Chandra surveys

Description : Extragalactic X-ray surveys over the past decade have dramatically improved understanding of the majority populations of active galactic nuclei (AGNs) over most of the history of the universe. Here we briefly highlight some of the exciting discoveries about AGN demography, physics, and ecology, with...
Repository : Europe PubMed Central
Language(s) : English

The obscured quasar population from optical, mid-infrared, and X-ray surveys

Description : Over the last few years, optical, mid-infrared and X-ray surveys have brought to light a significant number of candidate obscured AGN and, among them, many Type 2 quasars, the long-sought after "big cousins'' of local Seyfert 2 galaxies. However, despite the large amount of multi-wavelength data c...
Repository : arXiv
Language(s) : Undetermined

Found 162 documents, displaying page 1 of 17