ALBERT

Description: Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by the accretion of matter onto supermassive black holes. Although the measured width profiles of such jets on large scales agree with theories of magnetic collimation, the predicted structure on accretion disk scales at the jet launch point has not been detected. We report radio interferometry observations, at a wavelength of 1.3 millimeters, of the elliptical galaxy M87 that spatially resolve the base of the jet in this source. The derived size of 5.5 +/- 0.4 Schwarzschild radii is significantly smaller than the innermost edge of a retrograde accretion disk, suggesting that the M87 jet is powered by an accretion disk in a prograde orbit around a spinning black hole.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Doeleman, Sheperd S -- Fish, Vincent L -- Schenck, David E -- Beaudoin, Christopher -- Blundell, Ray -- Bower, Geoffrey C -- Broderick, Avery E -- Chamberlin, Richard -- Freund, Robert -- Friberg, Per -- Gurwell, Mark A -- Ho, Paul T P -- Honma, Mareki -- Inoue, Makoto -- Krichbaum, Thomas P -- Lamb, James -- Loeb, Abraham -- Lonsdale, Colin -- Marrone, Daniel P -- Moran, James M -- Oyama, Tomoaki -- Plambeck, Richard -- Primiani, Rurik A -- Rogers, Alan E E -- Smythe, Daniel L -- SooHoo, Jason -- Strittmatter, Peter -- Tilanus, Remo P J -- Titus, Michael -- Weintroub, Jonathan -- Wright, Melvyn -- Young, Ken H -- Ziurys, Lucy M -- New York, N.Y. -- Science. 2012 Oct 19;338(6105):355-8. doi: 10.1126/science.1224768. Epub 2012 Sep 27.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MIT Haystack Observatory, Off Route 40, Westford, MA 01886, USA. sdoeleman@haystack.mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23019611" target="_blank"〉PubMed〈/a〉

Description: Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A 'maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Riechers, Dominik A -- Bradford, C M -- Clements, D L -- Dowell, C D -- Perez-Fournon, I -- Ivison, R J -- Bridge, C -- Conley, A -- Fu, Hai -- Vieira, J D -- Wardlow, J -- Calanog, J -- Cooray, A -- Hurley, P -- Neri, R -- Kamenetzky, J -- Aguirre, J E -- Altieri, B -- Arumugam, V -- Benford, D J -- Bethermin, M -- Bock, J -- Burgarella, D -- Cabrera-Lavers, A -- Chapman, S C -- Cox, P -- Dunlop, J S -- Earle, L -- Farrah, D -- Ferrero, P -- Franceschini, A -- Gavazzi, R -- Glenn, J -- Solares, E A Gonzalez -- Gurwell, M A -- Halpern, M -- Hatziminaoglou, E -- Hyde, A -- Ibar, E -- Kovacs, A -- Krips, M -- Lupu, R E -- Maloney, P R -- Martinez-Navajas, P -- Matsuhara, H -- Murphy, E J -- Naylor, B J -- Nguyen, H T -- Oliver, S J -- Omont, A -- Page, M J -- Petitpas, G -- Rangwala, N -- Roseboom, I G -- Scott, D -- Smith, A J -- Staguhn, J G -- Streblyanska, A -- Thomson, A P -- Valtchanov, I -- Viero, M -- Wang, L -- Zemcov, M -- Zmuidzinas, J -- England -- Nature. 2013 Apr 18;496(7445):329-33. doi: 10.1038/nature12050.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, California 91125, USA. dr@astro.cornell.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23598341" target="_blank"〉PubMed〈/a〉

Description: Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty star-forming galaxies. However, the identification of gravitational lenses is often time-intensive, involving the sifting of large volumes of imaging or spectroscopic data to find few candidates. We used early data from the Herschel Astrophysical Terahertz Large Area Survey to demonstrate that wide-area submillimeter surveys can simply and easily detect strong gravitational lensing events, with close to 100% efficiency.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Negrello, Mattia -- Hopwood, R -- De Zotti, G -- Cooray, A -- Verma, A -- Bock, J -- Frayer, D T -- Gurwell, M A -- Omont, A -- Neri, R -- Dannerbauer, H -- Leeuw, L L -- Barton, E -- Cooke, J -- Kim, S -- da Cunha, E -- Rodighiero, G -- Cox, P -- Bonfield, D G -- Jarvis, M J -- Serjeant, S -- Ivison, R J -- Dye, S -- Aretxaga, I -- Hughes, D H -- Ibar, E -- Bertoldi, F -- Valtchanov, I -- Eales, S -- Dunne, L -- Driver, S P -- Auld, R -- Buttiglione, S -- Cava, A -- Grady, C A -- Clements, D L -- Dariush, A -- Fritz, J -- Hill, D -- Hornbeck, J B -- Kelvin, L -- Lagache, G -- Lopez-Caniego, M -- Gonzalez-Nuevo, J -- Maddox, S -- Pascale, E -- Pohlen, M -- Rigby, E E -- Robotham, A -- Simpson, C -- Smith, D J B -- Temi, P -- Thompson, M A -- Woodgate, B E -- York, D G -- Aguirre, J E -- Beelen, A -- Blain, A -- Baker, A J -- Birkinshaw, M -- Blundell, R -- Bradford, C M -- Burgarella, D -- Danese, L -- Dunlop, J S -- Fleuren, S -- Glenn, J -- Harris, A I -- Kamenetzky, J -- Lupu, R E -- Maddalena, R J -- Madore, B F -- Maloney, P R -- Matsuhara, H -- Michaowski, M J -- Murphy, E J -- Naylor, B J -- Nguyen, H -- Popescu, C -- Rawlings, S -- Rigopoulou, D -- Scott, D -- Scott, K S -- Seibert, M -- Smail, I -- Tuffs, R J -- Vieira, J D -- van der Werf, P P -- Zmuidzinas, J -- New York, N.Y. -- Science. 2010 Nov 5;330(6005):800-4. doi: 10.1126/science.1193420.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK. m.negrello@open.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21051633" target="_blank"〉PubMed〈/a〉

Description: Near a black hole, differential rotation of a magnetized accretion disk is thought to produce an instability that amplifies weak magnetic fields, driving accretion and outflow. These magnetic fields would naturally give rise to the observed synchrotron emission in galaxy cores and to the formation of relativistic jets, but no observations to date have been able to resolve the expected horizon-scale magnetic-field structure. We report interferometric observations at 1.3-millimeter wavelength that spatially resolve the linearly polarized emission from the Galactic Center supermassive black hole, Sagittarius A*. We have found evidence for partially ordered magnetic fields near the event horizon, on scales of ~6 Schwarzschild radii, and we have detected and localized the intrahour variability associated with these fields.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Johnson, Michael D -- Fish, Vincent L -- Doeleman, Sheperd S -- Marrone, Daniel P -- Plambeck, Richard L -- Wardle, John F C -- Akiyama, Kazunori -- Asada, Keiichi -- Beaudoin, Christopher -- Blackburn, Lindy -- Blundell, Ray -- Bower, Geoffrey C -- Brinkerink, Christiaan -- Broderick, Avery E -- Cappallo, Roger -- Chael, Andrew A -- Crew, Geoffrey B -- Dexter, Jason -- Dexter, Matt -- Freund, Robert -- Friberg, Per -- Gold, Roman -- Gurwell, Mark A -- Ho, Paul T P -- Honma, Mareki -- Inoue, Makoto -- Kosowsky, Michael -- Krichbaum, Thomas P -- Lamb, James -- Loeb, Abraham -- Lu, Ru-Sen -- MacMahon, David -- McKinney, Jonathan C -- Moran, James M -- Narayan, Ramesh -- Primiani, Rurik A -- Psaltis, Dimitrios -- Rogers, Alan E E -- Rosenfeld, Katherine -- SooHoo, Jason -- Tilanus, Remo P J -- Titus, Michael -- Vertatschitsch, Laura -- Weintroub, Jonathan -- Wright, Melvyn -- Young, Ken H -- Zensus, J Anton -- Ziurys, Lucy M -- New York, N.Y. -- Science. 2015 Dec 4;350(6265):1242-5. doi: 10.1126/science.aac7087. Epub 2015 Dec 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. mjohnson@cfa.harvard.edu. ; Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. ; Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. ; Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA. ; Department of Astronomy, Radio Astronomy Laboratory, 501 Campbell, University of California Berkeley, Berkeley, CA 94720-3411, USA. ; Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911. ; Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan. Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. ; Institute of Astronomy and Astrophysics, Academia Sinica, Post Office Box 23-141, Taipei 10617, Taiwan. ; Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. ; Academia Sinica Institute for Astronomy and Astrophysics (ASIAA), 645 N. A'ohoku Pl. Hilo, HI 96720, USA. ; Department of Astrophysics/Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, Post Office Box 9010, 6500 GL Nijmegen, Netherlands. ; Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada. Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada. ; Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748 Garching, Germany. ; James Clerk Maxwell Telescope, East Asia Observatory, 660 N. A'ohoku Place, University Park, Hilo, HI 96720, USA. ; Department of Physics, Joint Space-Science Institute, University of Maryland at College Park, Physical Sciences Complex, College Park, MD 20742, USA. ; National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan. Graduate University for Advanced Studies, Mitaka, 2-21-1 Osawa, Mitaka, Tokyo 181-8588. ; Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911. ; Max-Planck-Institut fur Radioastronomie, Auf dem Hugel 69, D-53121 Bonn, Germany. ; Owens Valley Radio Observatory, California Institute of Technology, 100 Leighton Lane, Big Pine, CA 93513-0968, USA. ; Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. Max-Planck-Institut fur Radioastronomie, Auf dem Hugel 69, D-53121 Bonn, Germany. ; Department of Astrophysics/Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, Post Office Box 9010, 6500 GL Nijmegen, Netherlands. Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26785487" target="_blank"〉PubMed〈/a〉

Description: We present an analysis of the multiwavelength behaviour of the blazar OJ 248 at z  = 0.939 in the period 2006–2013. We use low-energy data (optical, near-infrared, and radio) obtained by 21 observatories participating in the Gamma-Ray Large Area Space Telescope (GLAST)- AGILE Support Program of the Whole Earth Blazar Telescope, as well as data from the Swift (optical–UV and X-rays) and Fermi (-rays) satellites, to study flux and spectral variability and correlations among emissions in different bands. We take into account the effect of absorption by the Damped Lyman α intervening system at z  = 0.525. Two major outbursts were observed in 2006–2007 and in 2012–2013 at optical and near-IR wavelengths, while in the high-frequency radio light curves prominent radio outbursts are visible peaking at the end of 2010 and beginning of 2013, revealing a complex radio–optical correlation. Cross-correlation analysis suggests a delay of the optical variations after the -ray ones of about a month, which is a peculiar behaviour in blazars. We also analyse optical polarimetric and spectroscopic data. The average polarization percentage P is less than 3 per cent, but it reaches ~19 per cent during the early stage of the 2012–2013 outburst. A vague correlation of P with brightness is observed. There is no preferred electric vector polarization angle and during the outburst the linear polarization vector shows wide rotations in both directions, suggesting a complex behaviour/structure of the jet and possible turbulence. The analysis of 140 optical spectra acquired at the Steward Observatory reveals a strong Mg  ii broad emission line with an essentially stable flux of 6.2 x 10 – 15 erg cm – 2 s – 1 and a full width at half-maximum of 2053 km s – 1 .

Description: Measuring redshifted CO line emission is an unambiguous method for obtaining an accurate redshift and total cold gas content of optically faint, dusty starburst systems. Here, we report the first successful spectroscopic redshift determination of AzTEC J095942.9+022938 (‘COSMOS AzTEC-1’), the brightest 1.1 mm continuum source found in the AzTEC/James Clerk Maxwell Telescope survey (Scott et al.), through a clear detection of the redshifted CO (4–3) and CO (5–4) lines using the Redshift Search Receiver on the Large Millimeter Telescope. The CO redshift of z  = 4.3420 ± 0.0004 is confirmed by the detection of the redshifted 158 μm [C ii ] line using the Submillimeter Array. The new redshift and Herschel photometry yield L FIR  = (1.1 ± 0.1)  x  10 13 L and SFR  1300 M  yr –1 . Its molecular gas mass derived using the ultraluminous infrared galaxy conversion factor is 1.4 ± 0.2  x  10 11 M while the total interstellar medium mass derived from the 1.1 mm dust continuum is 3.7 ± 0.7  x  10 11 M assuming T d  = 35 K. Our dynamical mass analysis suggests that the compact gas disc ( r   1.1 kpc, inferred from dust continuum and spectral energy distribution analysis) has to be nearly face-on, providing a natural explanation for the uncommonly bright, compact stellar light seen by the HST . The [C ii ] line luminosity $L_{\rm [C\,\small {II}]}= 7.8\pm 1.1 \times 10^9 \,\mathrm{L}_{\odot }$ is remarkably high, but it is only 0.04 per cent of the total IR luminosity. AzTEC COSMOS-1 and other high redshift sources with a spatially resolved size extend the tight trend seen between [C ii ]/FIR ratio and FIR among IR-bright galaxies reported by Díaz-Santos et al. by more than an order of magnitude, supporting the explanation that the higher intensity of the IR radiation field is responsible for the ‘[C ii ] deficiency’ seen among luminous starburst galaxies.

Description: PKS 0521–36 is an active galactic nucleus (AGN) with uncertain classification. We investigate the properties of this source from radio to -rays. The broad emission lines in the optical and ultraviolet bands and steep radio spectrum indicate a possible classification as an intermediate object between broad-line radio galaxies (BLRG) and steep spectrum radio quasars (SSRQ). On pc-scales PKS 0521–36 shows a knotty structure similar to misaligned AGN. The core dominance and the -ray properties are similar to those estimated for other SSRQ and BLRG detected in -rays, suggesting an intermediate viewing angle with respect to the observer. In this context the flaring activity detected from this source by Fermi -Large Area Telescope between 2010 June and 2012 February is very intriguing. We discuss the -ray emission of this source in the framework of the structured jet scenario, comparing the spectral energy distribution (SED) of the flaring state in 2010 June with that of a low state. We present three alternative models corresponding to three different choices of the viewing angles v  = 6°, 15°, and 20°. We obtain a good fit for the first two cases, but the SED obtained with v  = 15° if observed at a small angle does not resemble that of a typical blazar since the synchrotron emission should dominate by a large factor (~100) the inverse Compton component. This suggests that a viewing angle between 6° and 15° is preferred, with the rapid variability observed during -ray flares favouring a smaller angle. However, we cannot rule out that PKS 0521–36 is the misaligned counterpart of a synchrotron-dominated blazar.

Description: We present Early Science observations with the Large Millimeter Telescope, AzTEC 1.1 mm continuum images and wide bandwidth spectra (73–111 GHz) acquired with the Redshift Search Receiver, towards four bright lensed submillimetre galaxies identified through the Herschel Lensing Survey-snapshot and the Submillimetre Common-User Bolometer Array-2 Cluster Snapshot Survey. This pilot project studies the star formation history and the physical properties of the molecular gas and dust content of the highest redshift galaxies identified through the benefits of gravitational magnification. We robustly detect dust continuum emission for the full sample and CO emission lines for three of the targets. We find that one source shows spectroscopic multiplicity and is a blend of three galaxies at different redshifts ( z  = 2.040, 3.252, and 4.680), reminiscent of previous high-resolution imaging follow-up of unlensed submillimetre galaxies, but with a completely different search method, that confirm recent theoretical predictions of physically unassociated blended galaxies. Identifying the detected lines as 12 CO ( J up  = 2–5) we derive spectroscopic redshifts, molecular gas masses, and dust masses from the continuum emission. The mean H 2 gas mass of the full sample is (2.0 ± 0.2)  x  10 11 M /μ, and the mean dust mass is (2.0 ± 0.2)  x  10 9 M /μ, where μ  2–5 is the expected lens amplification. Using these independent estimations we infer a gas-to-dust ratio of GDR   55–75, in agreement with other measurements of submillimetre galaxies. Our magnified high-luminosity galaxies fall on the same locus as other high-redshift submillimetre galaxies, extending the $L^{\prime }_{\rm CO}$ – L FIR correlation observed for local luminous and ultraluminous infrared galaxies to higher far-infrared and CO luminosities.