ALBERT

Description: We present the first scaling relation between weak-lensing galaxy cluster mass, M WL , and near-infrared luminosity, L K . Our results are based on 17 clusters observed with wide-field instruments on Subaru, the United Kingdom Infrared Telescope, the Mayall Telescope, and the MMT. We concentrate on the relation between projected 2D weak-lensing mass and spectroscopically confirmed luminosity within 1 Mpc, modelled as $M_{\rm WL} \propto L_{K}^b$ , obtaining a power-law slope of $b=0.83^{+0.27}_{-0.24}$ and an intrinsic scatter of $\sigma _{lnM_{\rm WL}|L_{K}}=10^{+8}_{-5}$ per cent. Intrinsic scatter of ~10 per cent is a consistent feature of our results regardless of how we modify our approach to measuring the relationship between mass and light. For example, deprojecting the mass and measuring both quantities within r 500 , that is itself obtained from the lensing analysis, yields $\sigma _{lnM_{\rm WL}|L_{K}}=10^{+7}_{-5}$ per cent and $b=0.97^{+0.17}_{-0.17}$ . We also find that selecting members based on their ( J – K ) colours instead of spectroscopic redshifts neither increases the scatter nor modifies the slope. Overall our results indicate that near-infrared luminosity measured on scales comparable with r 500 (typically 1 Mpc for our sample) is a low scatter and relatively inexpensive proxy for weak-lensing mass. Near-infrared luminosity may therefore be a useful mass proxy for cluster cosmology experiments.

Description: The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation. Sagittarius A* (Sgr A*), the compact source of radio, infrared and X-ray emission at the centre of the Milky Way, is the closest example of this phenomenon, with an estimated black hole mass that is 4,000,000 times that of the Sun. A long-standing astronomical goal is to resolve structures in the innermost accretion flow surrounding Sgr A*, where strong gravitational fields will distort the appearance of radiation emitted near the black hole. Radio observations at wavelengths of 3.5 mm and 7 mm have detected intrinsic structure in Sgr A*, but the spatial resolution of observations at these wavelengths is limited by interstellar scattering. Here we report observations at a wavelength of 1.3 mm that set a size of 37(+16)(-10) microarcseconds on the intrinsic diameter of Sgr A*. This is less than the expected apparent size of the event horizon of the presumed black hole, suggesting that the bulk of Sgr A* emission may not be centred on the black hole, but arises in the surrounding accretion flow.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Doeleman, Sheperd S -- Weintroub, Jonathan -- Rogers, Alan E E -- Plambeck, Richard -- Freund, Robert -- Tilanus, Remo P J -- Friberg, Per -- Ziurys, Lucy M -- Moran, James M -- Corey, Brian -- Young, Ken H -- Smythe, Daniel L -- Titus, Michael -- Marrone, Daniel P -- Cappallo, Roger J -- Bock, Douglas C-J -- Bower, Geoffrey C -- Chamberlin, Richard -- Davis, Gary R -- Krichbaum, Thomas P -- Lamb, James -- Maness, Holly -- Niell, Arthur E -- Roy, Alan -- Strittmatter, Peter -- Werthimer, Daniel -- Whitney, Alan R -- Woody, David -- England -- Nature. 2008 Sep 4;455(7209):78-80. doi: 10.1038/nature07245.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Massachusetts Institute of Technology (MIT) Haystack Observatory, Off Route 40, Westford, Massachusetts 01886, USA. sdoeleman@haystack.mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18769434" target="_blank"〉PubMed〈/a〉

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: In the cores of some clusters of galaxies the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime, leading to continuous 'cooling flows' of gas sinking towards the cluster centre, yet no such cooling flow has been observed. The low observed star-formation rates and cool gas masses for these 'cool-core' clusters suggest that much of the cooling must be offset by feedback to prevent the formation of a runaway cooling flow. Here we report X-ray, optical and infrared observations of the galaxy cluster SPT-CLJ2344-4243 (ref. 11) at redshift z = 0.596. These observations reveal an exceptionally luminous (8.2 x 10(45) erg s(-1)) galaxy cluster that hosts an extremely strong cooling flow (around 3,820 solar masses a year). Further, the central galaxy in this cluster appears to be experiencing a massive starburst (formation of around 740 solar masses a year), which suggests that the feedback source responsible for preventing runaway cooling in nearby cool-core clusters may not yet be fully established in SPT-CLJ2344-4243. This large star-formation rate implies that a significant fraction of the stars in the central galaxy of this cluster may form through accretion of the intracluster medium, rather than (as is currently thought) assembling entirely via mergers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McDonald, M -- Bayliss, M -- Benson, B A -- Foley, R J -- Ruel, J -- Sullivan, P -- Veilleux, S -- Aird, K A -- Ashby, M L N -- Bautz, M -- Bazin, G -- Bleem, L E -- Brodwin, M -- Carlstrom, J E -- Chang, C L -- Cho, H M -- Clocchiatti, A -- Crawford, T M -- Crites, A T -- de Haan, T -- Desai, S -- Dobbs, M A -- Dudley, J P -- Egami, E -- Forman, W R -- Garmire, G P -- George, E M -- Gladders, M D -- Gonzalez, A H -- Halverson, N W -- Harrington, N L -- High, F W -- Holder, G P -- Holzapfel, W L -- Hoover, S -- Hrubes, J D -- Jones, C -- Joy, M -- Keisler, R -- Knox, L -- Lee, A T -- Leitch, E M -- Liu, J -- Lueker, M -- Luong-Van, D -- Mantz, A -- Marrone, D P -- McMahon, J J -- Mehl, J -- Meyer, S S -- Miller, E D -- Mocanu, L -- Mohr, J J -- Montroy, T E -- Murray, S S -- Natoli, T -- Padin, S -- Plagge, T -- Pryke, C -- Rawle, T D -- Reichardt, C L -- Rest, A -- Rex, M -- Ruhl, J E -- Saliwanchik, B R -- Saro, A -- Sayre, J T -- Schaffer, K K -- Shaw, L -- Shirokoff, E -- Simcoe, R -- Song, J -- Spieler, H G -- Stalder, B -- Staniszewski, Z -- Stark, A A -- Story, K -- Stubbs, C W -- Suhada, R -- van Engelen, A -- Vanderlinde, K -- Vieira, J D -- Vikhlinin, A -- Williamson, R -- Zahn, O -- Zenteno, A -- England -- Nature. 2012 Aug 16;488(7411):349-52. doi: 10.1038/nature11379.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. mcdonald@space.mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22895340" target="_blank"〉PubMed〈/a〉

Description: In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z 〉 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z 〉 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vieira, J D -- Marrone, D P -- Chapman, S C -- De Breuck, C -- Hezaveh, Y D -- Weibeta, A -- Aguirre, J E -- Aird, K A -- Aravena, M -- Ashby, M L N -- Bayliss, M -- Benson, B A -- Biggs, A D -- Bleem, L E -- Bock, J J -- Bothwell, M -- Bradford, C M -- Brodwin, M -- Carlstrom, J E -- Chang, C L -- Crawford, T M -- Crites, A T -- de Haan, T -- Dobbs, M A -- Fomalont, E B -- Fassnacht, C D -- George, E M -- Gladders, M D -- Gonzalez, A H -- Greve, T R -- Gullberg, B -- Halverson, N W -- High, F W -- Holder, G P -- Holzapfel, W L -- Hoover, S -- Hrubes, J D -- Hunter, T R -- Keisler, R -- Lee, A T -- Leitch, E M -- Lueker, M -- Luong-Van, D -- Malkan, M -- McIntyre, V -- McMahon, J J -- Mehl, J -- Menten, K M -- Meyer, S S -- Mocanu, L M -- Murphy, E J -- Natoli, T -- Padin, S -- Plagge, T -- Reichardt, C L -- Rest, A -- Ruel, J -- Ruhl, J E -- Sharon, K -- Schaffer, K K -- Shaw, L -- Shirokoff, E -- Spilker, J S -- Stalder, B -- Staniszewski, Z -- Stark, A A -- Story, K -- Vanderlinde, K -- Welikala, N -- Williamson, R -- England -- Nature. 2013 Mar 21;495(7441):344-7. doi: 10.1038/nature12001. Epub 2013 Mar 13.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA. vieira@caltech.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23485967" target="_blank"〉PubMed〈/a〉

Description: We report high-angular-resolution measurements of polarized dust emission toward the low-mass protostellar system NGC 1333 IRAS 4A. We show that in this system the observed magnetic field morphology is in agreement with the standard theoretical models of the formation of Sun-like stars in magnetized molecular clouds at scales of a few hundred astronomical units; gravity has overcome magnetic support, and the magnetic field traces a clear hourglass shape. The magnetic field is substantially more important than turbulence in the evolution of the system, and the initial misalignment of the magnetic and spin axes may have been important in the formation of the binary system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Girart, Josep M -- Rao, Ramprasad -- Marrone, Daniel P -- New York, N.Y. -- Science. 2006 Aug 11;313(5788):812-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut de Ciencies de l'Espai (CSIC-IEEC), Campus UAB-Facultat de Ciencies, Torre C5-Parell 2, Bellaterra, Catalunya 08193, Spain. girart@ieec.uab.es〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16902132" 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 probe star formation in the environments of massive (~10 13 M ) dark matter haloes at redshifts of z ~ 1. This star formation is linked to a submillimetre clustering signal which we detect in maps of the Planck High Frequency Instrument that are stacked at the positions of a sample of high redshift ( z 〉 2) strongly lensed dusty star-forming galaxies (DSFGs) selected from the South Pole Telescope (SPT) 2500 deg 2 survey. The clustering signal has submillimetre colours which are consistent with the mean redshift of the foreground lensing haloes ( z ~ 1). We report a mean excess of star formation rate (SFR) compared to the field, of (2700 ± 700) M yr –1 from all galaxies contributing to this clustering signal within a radius of 3.5 arcmin from the SPT DSFGs. The magnitude of the Planck excess is in broad agreement with predictions of a current model of the cosmic infrared background. The model predicts that 80 per cent of the excess emission measured by Planck originates from galaxies lying in the neighbouring haloes of the lensing halo. Using Herschel maps of the same fields, we find a clear excess, relative to the field, of individual sources which contribute to the Planck excess. The mean excess SFR compared to the field is measured to be (370 ± 40) M yr –1 per resolved, clustered source. Our findings suggest that the environments around these massive z ~ 1 lensing haloes host intense star formation out to about 2 Mpc. The flux enhancement due to clustering should also be considered when measuring flux densities of galaxies in Planck data.

Description: Using the Australia Telescope Compact Array, we conducted a survey of CO J = 1 – 0 and J = 2 – 1 line emission towards strongly lensed high-redshift dusty star-forming galaxies (DSFGs) previously discovered with the South Pole Telescope (SPT). Our sample comprises 17 sources that had CO-based spectroscopic redshifts obtained with the Atacama Large Millimeter/submillimeter Array and the Atacama Pathfinder Experiment. We detect all sources with known redshifts in either CO J = 1 – 0 or J = 2 – 1. 12 sources are detected in the 7-mm continuum. The derived CO luminosities imply gas masses in the range (0.5–11) x 10 10 M and gas depletion time-scales t dep 〈 200 Myr, using a CO to gas mass conversion factor α CO = 0.8 M (K km s –1  pc 2 ) –1 . Combining the CO luminosities and dust masses, along with a fixed gas-to-dust ratio, we derive α CO factors in the range 0.4–1.8 M (K km s –1  pc 2 ) –1 , similar to what is found in other starbursting systems. We find small scatter in α CO values within the sample, even though inherent variations in the spatial distribution of dust and gas in individual cases could bias the dust-based α CO estimates. We find that lensing magnification factors based on the CO linewidth to luminosity relation (μ CO ) are highly unreliable, but particularly when μ 〈 5. Finally, comparison of the gas and dynamical masses suggest that the average molecular gas fraction stays relatively constant at z = 2–5 in the SPT DSFG sample.