Deep Silicate Absorption Features in Compton-Thick Active Galactic Nuclei Predominantly Arise Due to Dust in the Host Galaxy
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IRS Observations of Seyfert 1.8 and 1.9 Galaxies: a Comparison with Seyfert 1 and Seyfert 2 R
University of Kentucky UKnowledge Physics and Astronomy Faculty Publications Physics and Astronomy 12-10-2007 Spitzer IRS Observations of Seyfert 1.8 and 1.9 Galaxies: A Comparison with Seyfert 1 and Seyfert 2 R. P. Deo Georgia State University D. M. Crenshaw Georgia State University S. B. Kraemer Catholic University of America M. Dietrich Ohio State University Moshe Elitzur University of Kentucky, [email protected] See next page for additional authors Right click to open a feedback form in a new tab to let us know how this document benefits oy u. Follow this and additional works at: https://uknowledge.uky.edu/physastron_facpub Part of the Astrophysics and Astronomy Commons, and the Physics Commons Repository Citation Deo, R. P.; Crenshaw, D. M.; Kraemer, S. B.; Dietrich, M.; Elitzur, Moshe; Teplitz, H.; and Turner, T. J., "Spitzer IRS Observations of Seyfert 1.8 and 1.9 Galaxies: A Comparison with Seyfert 1 and Seyfert 2" (2007). Physics and Astronomy Faculty Publications. 203. https://uknowledge.uky.edu/physastron_facpub/203 This Article is brought to you for free and open access by the Physics and Astronomy at UKnowledge. It has been accepted for inclusion in Physics and Astronomy Faculty Publications by an authorized administrator of UKnowledge. For more information, please contact [email protected]. Authors R. P. Deo, D. M. Crenshaw, S. B. Kraemer, M. Dietrich, Moshe Elitzur, H. Teplitz, and T. J. Turner Spitzer IRS Observations of Seyfert 1.8 and 1.9 Galaxies: A Comparison with Seyfert 1 and Seyfert 2 Notes/Citation Information Published in The Astrophysical Journal, v. -
Arxiv:Astro-Ph/9902377V1 26 Feb 1999 Sus Uha H Omcxrybcgon.Ide,Tedis the Indeed, Background
The distribution of absorbing column densities among Seyfert 2 galaxies G. Risaliti Dipartimento di Astronomia e Scienza dello Spazio, Univerit`adi Firenze, L. E. Fermi 5, I-50125, Firenze, Italy R. Maiolino and M. Salvati Osservatorio Astrofisico di Arcetri, L. E. Fermi 5, I-50125 Firenze, Italy ABSTRACT We use hard X-ray data for an “optimal” sample of Seyfert 2 galaxies to derive the distribution of the gaseous absorbing column densities among obscured active nuclei in the local Universe. Of all Seyfert 2 galaxies in the sample, 75% are heavily obscured 23 −2 24 −2 (NH > 10 cm ) and about half are Compton thick (NH > 10 cm ). Intermediate type 1.8–1.9 Seyferts are characterized by an average NH much lower than “strict” Seyfert 2s. No correlation is found between NH and the intrinsic luminosity of the nuclear source. This NH distribution has important consequences for the synthesis of the cosmic X-ray background. Also, the large fraction of Compton thick objects implies that most of the obscuring gas is located within a radius of a few 10 pc from the nucleus. Subject headings: Galaxies: active — Galaxies: nuclei — Galaxies: Seyfert — X-rays: galaxies arXiv:astro-ph/9902377v1 26 Feb 1999 1. Introduction According to the so-called unified model (Antonucci 1993) the same engine is at work in all Active Galactic Nuclei (AGNs). The differences between type 1 and type 2 AGNs are ascribed solely to orientation effects: our line of sight to the nucleus may (type 2) or may not (type 1) be obstructed by optically thick material, perhaps distributed in a toroidal geometry. -
Lopsided Spiral Galaxies: Evidence for Gas Accretion
A&A 438, 507–520 (2005) Astronomy DOI: 10.1051/0004-6361:20052631 & c ESO 2005 Astrophysics Lopsided spiral galaxies: evidence for gas accretion F. Bournaud1, F. Combes1,C.J.Jog2, and I. Puerari3 1 Observatoire de Paris, LERMA, 61 Av. de l’Observatoire, 75014 Paris, France e-mail: [email protected] 2 Department of Physics, Indian Institute of Science, Bangalore 560012, India 3 Instituto Nacional de Astrofísica, Optica y Electrónica, Calle Luis Enrique Erro 1, 72840 Tonantzintla, Puebla, Mexico Received 3 January 2005 / Accepted 15 March 2005 Abstract. We quantify the degree of lopsidedness for a sample of 149 galaxies observed in the near-infrared from the OSUBGS sample, and try to explain the physical origin of the observed disk lopsidedness. We confirm previous studies, but for a larger sample, that a large fraction of galaxies have significant lopsidedness in their stellar disks, measured as the Fourier amplitude of the m = 1 component normalised to the average or m = 0 component in the surface density. Late-type galaxies are found to be more lopsided, while the presence of m = 2 spiral arms and bars is correlated with disk lopsidedness. We also show that the m = 1 amplitude is uncorrelated with the presence of companions. Numerical simulations were carried out to study the generation of m = 1viadifferent processes: galaxy tidal encounters, galaxy mergers, and external gas accretion with subsequent star formation. These simulations show that galaxy interactions and mergers can trigger strong lopsidedness, but do not explain several independent statistical properties of observed galaxies. To explain all the observational results, it is required that a large fraction of lopsidedness results from cosmological accretion of gas on galactic disks, which can create strongly lopsided disks when this accretion is asymmetrical enough. -
Probing the Physics of Narrow Line Regions in Active Galaxies II: the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)
Probing the Physics of Narrow Line Regions in Active Galaxies II: The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) Michael A. Dopita1,2, Prajval Shastri3, Rebecca Davies1, Lisa Kewley1,4, Elise Hampton1, Julia Scharw¨achter5, Ralph Sutherland1, Preeti Kharb3, Jessy Jose3, Harish Bhatt3, S. Ramya 3, Chichuan Jin6, Julie Banfield7, Ingyin Zaw8, St´ephanie Juneau9, Bethan James10 & Shweta Srivastava11 [email protected] ABSTRACT Here we describe the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph (WiFeS) mounted on the ANU 2.3m telescope located at the Siding Spring Observatory to deliver an integral field of 38×25 arcsec at a spectral resolution of R = 7000 in the red (530−710nm), and R = 3000 in the blue (340 − 560nm). From these data cubes we have extracted the Narrow Line Region (NLR) spectra from a 4 arc sec aperture centred on the nucleus. We also determine the Hβ and [O III] λ5007 fluxes in the narrow lines, the nuclear reddening, the reddening-corrected relative intensities of the observed emission lines, and the Hβ and [O III] λ5007 luminosities determined 1RSAA, Australian National University, Cotter Road, Weston Creek, ACT 2611, Australia 2Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah, Saudi Arabia 3Indian Institute of Astrophysics, Koramangala 2B Block, Bangalore 560034, India 4Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI, USA 5LERMA, Observatoire de Paris, CNRS, UMR 8112, 61 Avenue de l’Observatoire, 75014, Paris, France 6Qian Xuesen Laboratory for Space Technology, Beijing, China 7CSIRO Astronomy & Space Science, P.O. -
X-Ray Spectral Variability of Seyfert 2 Galaxies
Astronomy & Astrophysics manuscript no. Seyfert c ESO 2018 February 27, 2018 X-ray spectral variability of Seyfert 2 galaxies Hern´andez-Garc´ıa, L.1; Masegosa, J.1; Gonz´alez-Mart´ın, O.2; M´arquez, I.1 1 Instituto de Astrof´ısica de Andaluc´ıa, CSIC, Glorieta de la Astronom´ıa, s/n, 18008 Granada, Spain e-mail: [email protected] 2 Centro de radioastronom´ıa y Astrof´ısica (CRyA-UNAM), 3-72 (Xangari), 8701, Morelia, Mexico Received XXXX; accepted YYYY ABSTRACT Context. Variability across the electromagnetic spectrum is a property of active galactic nuclei (AGN) that can help constrain the physical properties of these galaxies. Nonetheless, the way in which the changes happen and whether they occur in the same way in every AGN are still open questions. Aims. This is the third in a series of papers with the aim of studying the X-ray variability of different families of AGN. The main purpose of this work is to investigate the variability pattern(s) in a sample of optically selected Seyfert 2 galaxies. Methods. We use the 26 Seyfert 2s in the V´eron-Cetty and V´eron catalog with data available from Chandra and/or XMM–Newton public archives at different epochs, with timescales ranging from a few hours to years. All the spectra of the same source were simultaneously fitted, and we let different parameters vary in the model. Whenever possible, short-term variations from the analysis of the light curves and/or long-term UV flux variations were studied. We divided the sample into Compton-thick and Compton-thin candidates to account for the degree of obscuration. -
Type II Supernovae As Probes of Environment Metallicity: Observations of Host H II Regions J
A&A 589, A110 (2016) Astronomy DOI: 10.1051/0004-6361/201527691 & c ESO 2016 Astrophysics Type II supernovae as probes of environment metallicity: observations of host H II regions J. P. Anderson1, C. P. Gutiérrez1; 2; 3, L. Dessart4, M. Hamuy3; 2, L. Galbany2; 3, N. I. Morrell5, M. D. Stritzinger6, M. M. Phillips5, G. Folatelli7, H. M. J. Boffin1, T. de Jaeger2; 3, H. Kuncarayakti2; 3, and J. L. Prieto8; 2 1 European Southern Observatory, Alonso de Córdova 3107, Casilla 19, Santiago, Chile e-mail: [email protected] 2 Millennium Institute of Astrophysics, Casilla 36-D, Santiago, Chile 3 Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile 4 Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Boulevard de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France 5 Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena, Chile 6 Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark 7 Instituto de Astrofísica de La Plata, Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, CONICET, Paseo del Bosque S/N, B1900FWA, La Plata, Argentina 8 Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile Received 3 November 2015 / Accepted 28 January 2016 ABSTRACT Context. Spectral modelling of type II supernova atmospheres indicates a clear dependence of metal line strengths on progenitor metallicity. This dependence motivates further work to evaluate the accuracy with which these supernovae can be used as environment metallicity indicators. Aims. -
190 Index of Names
Index of names Ancora Leonis 389 NGC 3664, Arp 005 Andriscus Centauri 879 IC 3290 Anemodes Ceti 85 NGC 0864 Name CMG Identification Angelica Canum Venaticorum 659 NGC 5377 Accola Leonis 367 NGC 3489 Angulatus Ursae Majoris 247 NGC 2654 Acer Leonis 411 NGC 3832 Angulosus Virginis 450 NGC 4123, Mrk 1466 Acritobrachius Camelopardalis 833 IC 0356, Arp 213 Angusticlavia Ceti 102 NGC 1032 Actenista Apodis 891 IC 4633 Anomalus Piscis 804 NGC 7603, Arp 092, Mrk 0530 Actuosus Arietis 95 NGC 0972 Ansatus Antliae 303 NGC 3084 Aculeatus Canum Venaticorum 460 NGC 4183 Antarctica Mensae 865 IC 2051 Aculeus Piscium 9 NGC 0100 Antenna Australis Corvi 437 NGC 4039, Caldwell 61, Antennae, Arp 244 Acutifolium Canum Venaticorum 650 NGC 5297 Antenna Borealis Corvi 436 NGC 4038, Caldwell 60, Antennae, Arp 244 Adelus Ursae Majoris 668 NGC 5473 Anthemodes Cassiopeiae 34 NGC 0278 Adversus Comae Berenices 484 NGC 4298 Anticampe Centauri 550 NGC 4622 Aeluropus Lyncis 231 NGC 2445, Arp 143 Antirrhopus Virginis 532 NGC 4550 Aeola Canum Venaticorum 469 NGC 4220 Anulifera Carinae 226 NGC 2381 Aequanimus Draconis 705 NGC 5905 Anulus Grahamianus Volantis 955 ESO 034-IG011, AM0644-741, Graham's Ring Aequilibrata Eridani 122 NGC 1172 Aphenges Virginis 654 NGC 5334, IC 4338 Affinis Canum Venaticorum 449 NGC 4111 Apostrophus Fornac 159 NGC 1406 Agiton Aquarii 812 NGC 7721 Aquilops Gruis 911 IC 5267 Aglaea Comae Berenices 489 NGC 4314 Araneosus Camelopardalis 223 NGC 2336 Agrius Virginis 975 MCG -01-30-033, Arp 248, Wild's Triplet Aratrum Leonis 323 NGC 3239, Arp 263 Ahenea -
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it. -
Ngc Catalogue Ngc Catalogue
NGC CATALOGUE NGC CATALOGUE 1 NGC CATALOGUE Object # Common Name Type Constellation Magnitude RA Dec NGC 1 - Galaxy Pegasus 12.9 00:07:16 27:42:32 NGC 2 - Galaxy Pegasus 14.2 00:07:17 27:40:43 NGC 3 - Galaxy Pisces 13.3 00:07:17 08:18:05 NGC 4 - Galaxy Pisces 15.8 00:07:24 08:22:26 NGC 5 - Galaxy Andromeda 13.3 00:07:49 35:21:46 NGC 6 NGC 20 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 7 - Galaxy Sculptor 13.9 00:08:21 -29:54:59 NGC 8 - Double Star Pegasus - 00:08:45 23:50:19 NGC 9 - Galaxy Pegasus 13.5 00:08:54 23:49:04 NGC 10 - Galaxy Sculptor 12.5 00:08:34 -33:51:28 NGC 11 - Galaxy Andromeda 13.7 00:08:42 37:26:53 NGC 12 - Galaxy Pisces 13.1 00:08:45 04:36:44 NGC 13 - Galaxy Andromeda 13.2 00:08:48 33:25:59 NGC 14 - Galaxy Pegasus 12.1 00:08:46 15:48:57 NGC 15 - Galaxy Pegasus 13.8 00:09:02 21:37:30 NGC 16 - Galaxy Pegasus 12.0 00:09:04 27:43:48 NGC 17 NGC 34 Galaxy Cetus 14.4 00:11:07 -12:06:28 NGC 18 - Double Star Pegasus - 00:09:23 27:43:56 NGC 19 - Galaxy Andromeda 13.3 00:10:41 32:58:58 NGC 20 See NGC 6 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 21 NGC 29 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 22 - Galaxy Pegasus 13.6 00:09:48 27:49:58 NGC 23 - Galaxy Pegasus 12.0 00:09:53 25:55:26 NGC 24 - Galaxy Sculptor 11.6 00:09:56 -24:57:52 NGC 25 - Galaxy Phoenix 13.0 00:09:59 -57:01:13 NGC 26 - Galaxy Pegasus 12.9 00:10:26 25:49:56 NGC 27 - Galaxy Andromeda 13.5 00:10:33 28:59:49 NGC 28 - Galaxy Phoenix 13.8 00:10:25 -56:59:20 NGC 29 See NGC 21 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 30 - Double Star Pegasus - 00:10:51 21:58:39 -
X-Ray Spectral Variability of Seyfert 2 Galaxies⋆
A&A 579, A90 (2015) Astronomy DOI: 10.1051/0004-6361/201526127 & c ESO 2015 Astrophysics X-ray spectral variability of Seyfert 2 galaxies L. Hernández-García1,J.Masegosa1, O. González-Martín2, and I. Márquez1 1 Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía, s/n, 18008 Granada, Spain e-mail: [email protected] 2 Centro de radioastronomía y Astrofísica (CRyA-UNAM), 3-72 (Xangari), 8701 Morelia, Mexico Received 18 March 2015 / Accepted 2 May 2015 ABSTRACT Context. Variability across the electromagnetic spectrum is a property of active galactic nuclei (AGN) that can help constrain the physical properties of these galaxies. Nonetheless, the way in which the changes happen and whether they occur in the same way in every AGN are still open questions. Aims. This is the third in a series of papers with the aim of studying the X-ray variability of different families of AGN. The main purpose of this work is to investigate the variability pattern(s) in a sample of optically selected Seyfert 2 galaxies. Methods. We use the 26 Seyfert 2s in the Véron-Cetty and Véron catalog with data available from Chandra and/or XMM-Newton public archives at different epochs, with timescales ranging from a few hours to years. All the spectra of the same source were simultaneously fitted, and we let different parameters vary in the model. Whenever possible, short-term variations from the analysis of the light curves and/or long-term UV flux variations were studied. We divided the sample into Compton-thick and Compton-thin candidates to account for the degree of obscuration. -
Unveiling the Buried Nucleus in NGC 1448 with Nustar
The Astrophysical Journal, 836:165 (13pp), 2017 February 20 https://doi.org/10.3847/1538-4357/836/2/165 © 2017. The American Astronomical Society. All rights reserved. A New Compton-thick AGN in Our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR A. Annuar1, D. M. Alexander1, P. Gandhi2, G. B. Lansbury1, D. Asmus3, D. R. Ballantyne4, F. E. Bauer5,6,7, S. E. Boggs8, P. G. Boorman2, W. N. Brandt9,10,11, M. Brightman12, F. E. Christensen13, W. W. Craig8,14, D. Farrah15, A. D. Goulding16, C. J. Hailey17, F. A. Harrison12, M. J. Koss18, S. M. LaMassa19, S. S. Murray20,21,24, C. Ricci5,22, D. J. Rosario1, F. Stanley1, D. Stern23, and W. Zhang19 1 Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK 2 Department of Physics & Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton, SO17 1BJ, UK 3 European Southern Observatory, Alonso de Cordova, Vitacura, Casilla 19001, Santiago, Chile 4 Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA 5 Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile 6 Millennium Institute of Astrophysics (MAS), Nuncio Monseñor Sótero Sanz 100, Providencia, Santiago, Chile 7 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA 8 Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA 9 Department of Astronomy -
The Success of Extragalactic Infrared Interferometry: from What We Have Learned to What to Expect
The success of extragalactic infrared interferometry: from what we have learned to what to expect Konrad R. W. Tristrama and Sebastian F. H¨onigb aEuropean Southern Observatory, Alonso de C´ordova 3107, Casilla 19001, Santiago, Chile bDepartment of Physics & Astronomy, University of Southampton, Southampton, SO17 1BJ, UK ABSTRACT Infrared interferometry has lead to a breakthrough in the investigation of Active Galactic Nuclei (AGN) by allowing to resolve structures on sizes of less than a few parsecs in nearby galaxies. Measurements in the near- infrared probe the innermost, hottest dust surrounding the central engine and the interferometrically determined sizes roughly follow those inferred from reverberation measurements. Interferometry in the mid-infrared has revealed parsec-sized, warm dust distributions with a clear two component structure: a disk-like component and polar emission { challenging the long-standing picture of the \dusty torus". New beam combiners are starting to resolve the kinematic structure of the broad line region and are expected to provide true images of the dust emission. Nevertheless, most AGN will remain only marginally resolved by current arrays and next generation facilities, such as the Planet Formation Imager (PFI), will be required to fully resolve out larger samples of AGN. Keywords: Infrared Interferometry, galaxies: nuclei, galaxies: Seyfert, galaxies: active 1. INTRODUCTION In astronomy, long baseline infrared interferometry is used to study compact thermal emission as well as compact line emission (e.g. using the Brγ line at 2:166µm). For the coherent combination of light from astronomical objects, sufficiently high signal to noise ratios are required in order to detect the fringes and measure their contrast.