Smita Mathur
Total Page:16
File Type:pdf, Size:1020Kb

Load more
Recommended publications
-
Chandra LETGS Observation of the Variable NLS1 Galaxy Ark 564⋆
A&A 551, A95 (2013) Astronomy DOI: 10.1051/0004-6361/201220424 & c ESO 2013 Astrophysics Chandra LETGS observation of the variable NLS1 galaxy Ark 564 J. M. Ramírez Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), PO Box 025304, Caracas 1020A, Venezuela e-mail: [email protected] Received 21 September 2012 / Accepted 18 January 2013 ABSTRACT We present an analysis of the 100 ks X-ray spectrum of the narrow-line Seyfert 1 Galaxy Ark 564, taken with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra.Usingχ2 statistics, several continuum models of the time-averaged spectrum of this object are compared, obtaining a semi-empirical solution for the description of the intrinsic emission continuum and a physical solution for the intrinsic absorption of the system. We find that the 0.1−10 keV spectrum can be well described by a power law plus two thermal components that account for the soft step. We are also able to detect and measure several narrow, unresolved absorption lines arising from highly ionized species of C, N, O, and Fe. The material seems to have a velocity consistent with the 20 −2 systemic velocity of the galaxy. This piece of evidence, in addition to the very low observed column density of NH ∼ 10 cm ,isin good agreement with the scenario of a transverse biconical outflow with a gas density of n 3 × 1012 cm−3 at distances beyond the broad-line region r 10 lt-days, but a dust torus origin cannot be ruled out. Key words. galaxies: Seyfert – line: identification – quasars: absorption lines 1. -
June 2013 BRAS Newsletter
www.brastro.org June 2013 What's in this issue: PRESIDENT'S MESSAGE .............................................................................................................................. 2 NOTES FROM THE VICE PRESIDENT ........................................................................................................... 3 MESSAGE FROM THE HRPO ...................................................................................................................... 4 OBSERVING NOTES ..................................................................................................................................... 6 MAY ASTRONOMICAL EVENTS .................................................................................................................... 9 PRESIDENT'S MESSAGE Greetings Everyone, Summer is here and with it the humidity and bugs, but I hope that won't stop you from getting out to see some of the great summer time objects in the sky. Also, Saturn is looking quite striking as the rings are now tilted at a nice angle allowing us to see the Casini Division and shadows on and from the planet. Don't miss it! I've been asked by BREC to make sure our club members are all aware of the Park Rules listed on BREC's website. Many of the rules are actually ordinances enacted by the city of Baton Rouge (e.g., No smoking permitted in public areas, No alcohol brought onto or sold on BREC property, No Gambling, No Firearms or Weapons, etc.) Please make sure you observe all of the Park Rules while at the HRPO and provide good examples for the general public. (Many of which are from outside East Baton Rouge Parish and are likely unaware of some of the policies.) For a full list of BREC's Park Rules, you may visit their Park Rules section of their website at http://brec.org/index.cfm/page/555/n/75 I'm sorry I had to miss the outing to LIGO, but it will be good to see some folks again at our meeting on Monday, June 10th. -
Profile Variability of the Hα and Hβ Broad Emission Lines in NGC 5548
Astronomy & Astrophysics manuscript no. (will be inserted by hand later) Profile variability of the Hα and Hβ broad emission lines in NGC 5548 A.I. Shapovalova1,5, V.T. Doroshenko2,7, N.G. Bochkarev2, A.N. Burenkov1,5, L. Carrasco3, V.H. Chavushyan3, S. Collin4, J.R. Vald´es3, N. Borisov1, A.-M. Dumont4, V.V. Vlasuyk1, I. Chillingarian2, I.S. Fioktistova1, and O.M. Martinez6 1 Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz, Karachaevo-Cherkesia, 369167, Russia 2 Sternberg Astronomical Institute, University of Moscow, Universitetskij Prospect 13, Moscow 119899, Russia 3 Instituto Nacional de Astrof´isica, Optica y Electr´onica, INAOE, Apartado Postal 51 y 216, 7200, Puebla, Pue., M´exico 4 LUTH, Observatoire de Paris, Section de Meudon, Place Janssen, 92195, Meudon France 5 Isaac Newton Institute of Chile, SAO Branch, Russia 6 Benem´erita Universidad Aut´onoma de Puebla, Facultad de Ciencias F´ısico-Matem´aticas, Apdo. Postal 1152, C.P. 72000, Puebla, Pue. M´exico 7 Isaac Newton Institute of Chile, Crimean Branch, Ukraine Received: 10 November 2003 / Accepted: 26 April 2004 Abstract. Between 1996 and 2002, we have carried out a spectral monitoring program for the Seyfert galaxy NGC 5548 with the 6 m and 1 m telescopes of SAO (Russia) and with the 2.1 m telescope of Guillermo Haro Observatory (GHO) at Cananea, M´exico. High quality spectra with S/N> 50 in the continuum near Hα and Hβ were obtained, covering the spectral range ∼(4000 – 7500) A˚ with a (4.5 to 15) A-resolution.˚ We found that both the flux in the lines and the continuum gradually decreased, reaching minimum values during May-June 2002. -
Also Available in PDF
University of Hawai‘i, Institute for Astronomy Publications in Calendar Year 2000 PUBLICATIONS Investigating the Link between Cometary and Interstellar Material. A&A, 353, 1101–1114 (2000) The following articles and books were published dur- ing calendar year 2000. The names of IfA authors Boehnhardt, H.; Hainaut, O.; Delahodde, C.; West, R.; are in boldface. For an html version of this list Meech, K.; Marsden, B. A Pencil-Beam Search for Dis- with links, go to http://www.ifa.hawaii.edu/publications/ tant TNOs at the ESO NTT. In Minor Bodies in the Outer 2000pubs.html. More recent publications are listed at Solar System, ed. A. Fitzsimmons, D. Jewitt, & R. M. http://www.ifa.hawaii.edu/publications/preprints/. West. ESO Astrophysics Symposia (Springer), 117–123 (2000) Barger, A. J.; Cowie, L. L.; Richards, E. A. Mapping the Evolution of High-Redshift Dusty Galaxies with Submil- Boesgaard, A. M. Review of Stellar Abundance Results from limeter Observations of a Radio-selected Sample. AJ, Large Telescopes. Proc. SPIE, 4005, 142–149 (2000) 119, 2092–2109 (2000) Boesgaard, A. M.; Stephens, A.; King, J. R.; Deliyannis, Barucci, M. A.; Romon, J.; Doressoundiram, A.; Tholen, C. P. Chemical Abundances in Globular Cluster Turn-Off D. J. Compositional Surface Diversity in the Trans-Nep- Stars from Keck/HIRES Observations. Proc. SPIE, 4005, tunian Objects. AJ, 120, 496–500 (2000) 274–284 (2000) Baudoz, P.; Mouillet, D.; Beuzit, J.-L.; Mekarnia, D.; Rab- Brandner, W.; Grebel, E. K.; Chu, Y.; Dottori, H.; Brandl, bia, Y.; Gay, J.; Schneider, J.-L. First Results of the B.; Richling, S.; Yorke, H. -
Gamma-Ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei
galaxies Review Gamma-ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei Yoshiyuki Inoue 1,2,3,* , Dmitry Khangulyan 4 and Akihiro Doi 5,6 1 Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan 2 Interdisciplinary Theoretical & Mathematical Science Program (iTHEMS), RIKEN, 2-1 Hirosawa, Saitama 351-0198, Japan 3 Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa 277-8583, Japan 4 Department of Physics, Rikkyo University, Nishi-Ikebukuro 3-34-1, Toshima-ku, Tokyo 171-8501, Japan; [email protected] 5 Institute of Space and Astronautical Science JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210, Japan; [email protected] 6 Department of Space and Astronautical Science, The Graduate University for Advanced Studies (SOKENDAI), 3-1-1 Yoshinodai, Chuou-ku, Sagamihara, Kanagawa 252-5210, Japan * Correspondence: [email protected] Abstract: To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and Gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the existence of weak non-thermal coronal activity. In addition, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10 year survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current Citation: Inoue, Y.; Khangulyan, D.; observational understanding of AGN coronae and describes how AGN coronae generate high-energy Doi, A. -
The Applicability of Far-Infrared Fine-Structure Lines As Star Formation
A&A 568, A62 (2014) Astronomy DOI: 10.1051/0004-6361/201322489 & c ESO 2014 Astrophysics The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types? Ilse De Looze1, Diane Cormier2, Vianney Lebouteiller3, Suzanne Madden3, Maarten Baes1, George J. Bendo4, Médéric Boquien5, Alessandro Boselli6, David L. Clements7, Luca Cortese8;9, Asantha Cooray10;11, Maud Galametz8, Frédéric Galliano3, Javier Graciá-Carpio12, Kate Isaak13, Oskar Ł. Karczewski14, Tara J. Parkin15, Eric W. Pellegrini16, Aurélie Rémy-Ruyer3, Luigi Spinoglio17, Matthew W. L. Smith18, and Eckhard Sturm12 1 Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000 Gent, Belgium e-mail: [email protected] 2 Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle Str. 2, 69120 Heidelberg, Germany 3 Laboratoire AIM, CEA, Université Paris VII, IRFU/Service d0Astrophysique, Bat. 709, 91191 Gif-sur-Yvette, France 4 UK ALMA Regional Centre Node, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK 5 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 6 Laboratoire d0Astrophysique de Marseille − LAM, Université Aix-Marseille & CNRS, UMR7326, 38 rue F. Joliot-Curie, 13388 Marseille CEDEX 13, France 7 Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK 8 European Southern Observatory, Karl -
The Soft X-Ray Variability and Spectrum of 1H0419-577From A
The Soft X-ray Variability and Spectrum of 1H0419-577from a long EUVE Observation H. L. Marshall 1 Eureka Scientific, Inc., 2452 Delmer St, Suite 100, Oakland, CA, 94602 J. P. Halpern Columbia University K. Leighly Columbia University Received ; accepted 1Mailing address: 5 Whipple Rd., Lexington, MA 02173. 2 ABSTRACT The active galaxy associatedwith the hard X-ray source1H0419-577was observedwith EUVE for about 25 days to obtain a long, contiguouslight curve and an EUV spectrum. An EUV sourcewas detectedwhich was about asbright asthe AGN and was later identified asan AM Her type system(Halpern et al. 1999). The AGN showedvariations as large as a factor of two over 5-10day time scalesand occasionallyvaried by 20-30%in < 0.5day. The spectrum is dominated by a continuum that is poorly fit by a simple powerlaw. There are possibleemissionlines without positive identifications but the lines are likely to be spurious. Subject headings: quasars - Individual: LB1727 -3- 1. Introduction There were less than 10 active galactic nuclei (AGN) detected in the EUVE all-sky survey that were bright enough to be considered detected unambiguously (Marshall, Fruscione, & Carone 1995). Of these, only a few have brbad lines and are bright enough to be detected well using the EUVE spectrometer. There has been significant controversy regarding the extreme ultraviolet (EUV) spectra of the few AGN that have been observed. While there are claims of possible emission lines in some active galaxies (NGC 5548: Kaastra et al. (1995); Mrk 478 and Ton S180 Hwang, C.-Y. &: Bowyer, S. 1997), there is also evidence that the AGN spectra are dominated by continua and that any lines must very weak (Mrk 478: Marshall et al. -
Optical Astronomy Observatories
NATIONAL OPTICAL ASTRONOMY OBSERVATORIES NATIONAL OPTICAL ASTRONOMY OBSERVATORIES FY 1994 PROVISIONAL PROGRAM PLAN June 25, 1993 TABLE OF CONTENTS I. INTRODUCTION AND PLAN OVERVIEW 1 II. SCIENTIFIC PROGRAM 3 A. Cerro Tololo Inter-American Observatory 3 B. Kitt Peak National Observatory 9 C. National Solar Observatory 16 III. US Gemini Project Office 22 IV. MAJOR PROJECTS 23 A. Global Oscillation Network Group (GONG) 23 B. 3.5-m Mirror Project 25 C. WIYN 26 D. SOAR 27 E. Other Telescopes at CTIO 28 V. INSTRUMENTATION 29 A. Cerro Tololo Inter-American Observatory 29 B. Kitt Peak National Observatory 31 1. KPNO O/UV 31 2. KPNO Infrared 34 C. National Solar Observatory 38 1. Sacramento Peak 38 2. Kitt Peak 40 D. Central Computer Services 44 VI. TELESCOPE OPERATIONS AND USER SUPPORT 45 A. Cerro Tololo Inter-American Observatory 45 B. Kitt Peak National Observatory 45 C. National Solar Observatory 46 VII. OPERATIONS AND FACILITIES MAINTENANCE 46 A. Cerro Tololo 47 B. Kitt Peak 48 C. NSO/Sacramento Peak 48 D. NOAO Tucson Headquarters 49 VIII. SCIENTIFIC STAFF AND SUPPORT 50 A. CTIO 50 B. KPNO 50 C. NSO 51 IX. PROGRAM SUPPORT 51 A. NOAO Director's Office 51 B. Central Administrative Services 52 C. Central Computer Services 52 D. Central Facilities Operations 53 E. Engineering and Technical Services 53 F. Publications and Information Resources 53 X. RESEARCH EXPERIENCES FOR UNDERGRADUATES PROGRAM 54 XI. BUDGET 55 A. Cerro Tololo Inter-American Observatory 56 B. Kitt Peak National Observatory 56 C. National Solar Observatory 57 D. Global Oscillation Network Group 58 E. -
The Ionized Nuclear Environment in NGC 985 As Seen by Chandra And
The ionized nuclear environment in NGC 985 as seen by Chandra and BeppoSAX Y. Krongold1, F. Nicastro1, M. Elvis1, N.S. Brickhouse1, S. Mathur2, A. Zezas1 ABSTRACT We investigate the ionized environment of the Seyfert 1 galaxy NGC 985 with a new Chandra-HETGS observation and an archival BeppoSAX observation. Both spectra exhibit strong residuals to a single powerlaw model, indicating the presence of an ionized absorber and a soft excess. A detailed model over the Chandra data shows that the 0.6-8 keV intrinsic continuum can be well represented by a powerlaw (Γ ≈ 1.6) plus a blackbody component (kT=0.1 keV). Two absorption components are clearly required to fit the absorption features observed in the Chandra spectrum. The components have a difference of 29 in ionization parameter and 3 in column density. The presence of the low ionization component is evidenced by an Fe M-shell unresolved transition array (UTA) produced by charge states vii to xiii. The high ionization phase is required by the presence of broad absorption features arising from several blends of Fe L-shell transitions (Fe xvii-xxii). A third highly ionized component might also be present, but the data does not allow to constrain its properties. Though poorly constrained, the outflow velocities of the components (581 ± 206 km s−1 for the high ionization phase and 197 ± 184 km s−1 for the low ionization one) are consistent with each other, and with the outflow velocities of the absorption components observed in the UV. In arXiv:astro-ph/0409490v1 21 Sep 2004 addition, the low ionization component produces significant amounts of O vi, N v, and C iv which suggests that a single outflow produces the UV and X-ray features. -
188633377.Pdf
The Astrophysical Journal Supplement Series, 225:29 (15pp), 2016 August doi:10.3847/0067-0049/225/2/29 © 2016. The American Astronomical Society. All rights reserved. EVIDENCE FOR PERIODICITY IN 43 YEAR-LONG MONITORING OF NGC 5548 E. Bon1,2, S. Zucker3, H. Netzer4, P. Marziani5, N. Bon1,2, P. JovanoviĆ1,2, A. I. Shapovalova6, S. Komossa7, C. M. Gaskell8,L.Č. PopoviĆ1,2, S. Britzen7, V. H. Chavushyan9, A. N. Burenkov6, S. Sergeev10, G. La Mura11, J. R. Valdés9, and M. Stalevski1,12,13 1 Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia 2 Isaac Newton Institute of Chile, Yugoslavia Branch Belgrade, Serbia 3 Department of Geosciences, Tel-Aviv University, Tel-Aviv 6997801, Israel 4 School of Physics and Astronomy and the Wise Observatory, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 6997801, Israel 5 INAF, Osservatorio Astronomico di Padova, Padova, Italy 6 Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz, Karachaevo-Cherkesia 369167, Russia 7 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany 8 Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064, USA 9 Instituto Nacional de Astrofsica, Óptica y Electrónica, Apartado Postal 51, CP 72000, Puebla, Pue, Mexico, Mexico 10 Crimean Astrophysical Observatory, P/O Nauchny, Republic of Crimea 298409, Russia 11 Dipartimento di Fisica e Astronomia “G. Galilei,” Università degli Studi di Padova, Vicolo dell’Osservatorio 3, I-35122—Padova, Italy 12 Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Casilla 36-D Santiago, Chile 13 Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281-S9, Gent, B-9000, Belgium Received 2016 April 10; revised 2016 June 11; accepted 2016 June 14; published 2016 August 23 ABSTRACT We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. -
1987Apj. . .321. .233E the Astrophysical Journal, 321
.233E The Astrophysical Journal, 321:233-250,19S7 October 1 © 1987. The American Astronomical Society. All rights reserved. Printed in U.S.A. .321. 1987ApJ. BROAD-BAND PROPERTIES OF THE CfA SEYFERT GALAXIES. II. INFRARED TO MILLIMETER PROPERTIES R. A. Edelson Owens Valley Radio Observatory, California Institute of Technology M. A. Malkan1,2 Department of Astronomy, University of California, Los Angeles AND G. H. Rieke Steward Observatory, University of Arizona Received 1986 November 14; accepted 1987 March 18 ABSTRACT Observations between 1.2 jum and 1.3 mm are presented for an unbiased, spectroscopically selected sample of 48 Seyfert galaxies. Most have complete infrared detections, but none were detected at 1.3 mm. The infrared spectra of optically selected Seyfert 2 galaxies are steep (a2.2_25/an= -1.56), in sharp contrast to optically selected quasars, which have flat infrared spectra (â2 2_25Aim = —1.09). This suggests that the infrared emission is predominantly thermal in Seyfert 2 galaxies and nonthermal in quasars. For optically selected Seyfert 1 galaxies, a2.2_25/im= -1.15, and -70% have flat spectra similar to quasars and unlike Seyfert 2 galaxies. Thus, the near- and mid-infrared emission from most Seyfert 1 galaxies appears to be dominated by non- thermal radiation, although thermal dust radiation is clearly important for others. Half of the objects detected at three or more IRAS wavelengths have far-infrared spectra which turn over shortward of 100 /un. For the relatively dust-free Seyfert 1 galaxies, this suggests that the infrared emission is dominated by unreprocessed radiation from a synchrotron self-absorbed source of the order of a light-day in size, about the same size as the hypothesized accretion disks. -
Jet-Powered Molecular Hydrogen Emission from Radio Galaxies
JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Ogle, Patrick, Francois Boulanger, Pierre Guillard, Daniel A. Evans, Robert Antonucci, P. N. Appleton, Nicole Nesvadba, and Christian Leipski. “JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES.” The Astrophysical Journal 724, no. 2 (November 11, 2010): 1193–1217. © 2010 The American Astronomical Society As Published http://dx.doi.org/10.1088/0004-637x/724/2/1193 Publisher IOP Publishing Version Final published version Citable link http://hdl.handle.net/1721.1/95698 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The Astrophysical Journal, 724:1193–1217, 2010 December 1 doi:10.1088/0004-637X/724/2/1193 C 2010. The American Astronomical Society. All rights reserved. Printed in the U.S.A. JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES Patrick Ogle1, Francois Boulanger2, Pierre Guillard1, Daniel A. Evans3, Robert Antonucci4, P. N. Appleton5, Nicole Nesvadba2, and Christian Leipski6 1 Spitzer Science Center, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125, USA; [email protected] 2 Institut d’Astrophysique Spatiale, Universite Paris-Sud 11, Bat. 121, 91405 Orsay Cedex, France 3 MIT Center for Space Research, Cambridge, MA 02139, USA 4 Physics Department, University of California, Santa Barbara, CA 93106, USA 5 NASA Herschel Science Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125, USA 6 Max-Planck Institut fur¨ Astronomie (MPIA), Konigstuhl¨ 17, D-69117 Heidelberg, Germany Received 2009 November 10; accepted 2010 September 22; published 2010 November 11 ABSTRACT H2 pure-rotational emission lines are detected from warm (100–1500 K) molecular gas in 17/55 (31% of) radio galaxies at redshift z<0.22 observed with the Spitzer IR Spectrograph.