ar X iv : a st ro - p h / 04 01 12 9 v 1 8 Ja n 20 04 Fact : Many SCUBA galaxies harbour AGNs
نویسندگان
چکیده
Deep SCUBA surveys have uncovered a large population of ultra-luminous galaxies at z > 1. These sources are often assumed to be starburst galaxies, but there is growing evidence that a substantial fraction host an AGN (i.e., an accreting super-massive black hole). We present here possibly the strongest evidence for this viewpoint to date: the combination of ultra-deep X-ray observations (the 2 Ms Chandra Deep Field-North) and deep optical spectroscopic data. We argue that upward of 38% of bright (f850µm ≥ 5 mJy) SCUBA galaxies host an AGN, a fraction of which are obscured QSOs (i.e., LX > 3 × 10 44 erg s −1). However, using evidence from a variety of analyses, we argue that in almost all cases the AGNs are not bolometrically important (i.e., < 20%). Thus, star formation appears to dominate their bolometric output. A substantial fraction of bright SCUBA galaxies show evidence for binary AGN activity. Since these systems appear to be interacting and merging at optical/near-IR wavelengths, their super-massive black holes will eventually coalesce.
منابع مشابه
ar X iv : a st ro - p h / 04 01 12 2 v 2 1 9 Ja n 20 04 High Energy Gamma - Ray Astronomy
The physics results of high energy γ-ray astronomy are reported, emphasizing recent achievements with ground-based detectors. This includes some of the instrumental developments and latest projects. The fundamental contribution of the field to the question of Cosmic Ray origin is highlighted.
متن کاملar X iv : a st ro - p h / 04 01 55 8 v 1 2 6 Ja n 20 04 Cepheids and Long Period Variables in NGC 4395
Repeated imaging observations of NGC 4395 were made with the WIYN 3.5 m and the KPNO 2.1 m telescopes. From the photometry of the resolved brighter stars in this galaxy eleven Cepheids with periods ranging between 12 and 90 days have been identified. The true distance modulus has been derived from the apparent distance moduli in g, r and i.
متن کاملar X iv : m at h / 04 01 12 6 v 1 [ m at h . N T ] 1 3 Ja n 20 04 THREE LECTURES ON THE RIEMANN ZETA - FUNCTION
متن کامل
ar X iv : a st ro - p h / 04 01 29 1 v 1 1 5 Ja n 20 04 INTEGRAL Spectrometer Analysis of GRB 030227 & GRB 030131
The spectrometer SPI on board INTEGRAL is capable of high-resolution spectroscopic studies in the energy range 20 keV to 8 MeV for GRBs which occur within the fully coded field of view (16 • corner to corner). Six GRBs occurred within the SPI field of view between October 2002 and November 2003. We present results of the analysis of the first two GRBs detected by SPI after the payload performan...
متن کاملar X iv : a st ro - p h / 04 01 42 8 v 1 2 1 Ja n 20 04 IS THE LOCAL BUBBLE DEAD ?
We give a summary of the current state of Local Bubble research, resulting from the discussions of a dedicated panel meeting. After more than 25 years of intense observational and theoretical work, we are still far from a coherent picture, although a probable one emerges at the horizon. A multi-supernova origin seems to be the best guess, with non-equilibrium cooling and soft X-ray emission acc...
متن کامل