Spatial and Kinematical Lopsidedness of Atomic Hydrogen in the Ursa
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1. Introduction
THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other. -
University of Southampton Research Repository Eprints Soton
University of Southampton Research Repository ePrints Soton Copyright © and Moral Rights for this thesis are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder/s. The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given e.g. AUTHOR (year of submission) "Full thesis title", University of Southampton, name of the University School or Department, PhD Thesis, pagination http://eprints.soton.ac.uk UNIVERSITY OF SOUTHAMPTON FACULTY OF PHYSICAL SCIENCES AND ENGINEERING Physics And Astronomy Fast Spectral Variability in the X-ray Emission of Accreting Black Holes by Chris J. Skipper Thesis for the degree of Doctor of Philosophy October 2013 UNIVERSITY OF SOUTHAMPTON ABSTRACT FACULTY OF PHYSICAL SCIENCES AND ENGINEERING Physics And Astronomy Doctor of Philosophy FAST SPECTRAL VARIABILITY IN THE X-RAY EMISSION OF ACCRETING BLACK HOLES by Chris J. Skipper The X-ray emission from accreting black holes provides the perfect probe for testing the geometry, behaviour and conditions present in the innermost regions of the accretion flow. In this thesis I use X-ray spectral analysis to investigate the properties of accret- ing black holes that extend over several orders of magnitude in accretion rate (m˙ E) and black hole mass (MBH), from the stellar mass black holes in X-ray binary systems (XRBs) to the supermassive black holes in active galactic nuclei (AGN). -
Classification of Galaxies Using Fractal Dimensions
UNLV Retrospective Theses & Dissertations 1-1-1999 Classification of galaxies using fractal dimensions Sandip G Thanki University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/rtds Repository Citation Thanki, Sandip G, "Classification of galaxies using fractal dimensions" (1999). UNLV Retrospective Theses & Dissertations. 1050. http://dx.doi.org/10.25669/8msa-x9b8 This Thesis is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in UNLV Retrospective Theses & Dissertations by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. -
The Medusa Merger in High Resolution 12CO 2–1 Maps
A&A 569, A6 (2014) Astronomy DOI: 10.1051/0004-6361/201423548 & c ESO 2014 Astrophysics Molecular tendrils feeding star formation in the Eye of the Medusa The Medusa merger in high resolution 12CO 2–1 maps S. König1,S.Aalto2, L. Lindroos2,S.Muller2, J. S. Gallagher III3,R.J.Beswick4, G. Petitpas5, and E. Jütte6 1 Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d’Hères, France e-mail: [email protected] 2 Chalmers University of Technology, Department of Earth and Space Sciences, Onsala Space Observatory, 43992 Onsala, Sweden 3 Department of Astronomy, University of Wisconsin, 475 N. Charter Street, Madison, WI 53706, USA 4 University of Manchester, Jodrell Bank Centre for Astrophysics, Oxford Road, Manchester, M13 9PL, UK 5 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 6 Astronomisches Institut Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany Received 31 January 2014 / Accepted 23 June 2014 ABSTRACT Studying molecular gas properties in merging galaxies gives us important clues to the onset and evolution of interaction-triggered starbursts. NGC 4194 (the Medusa merger) is particularly interesting to study, since its FIR-to-CO luminosity ratio rivals that of ultraluminous galaxies (ULIRGs), despite its lower luminosity compared to ULIRGs, which indicates a high star formation efficiency (SFE) that is relative to even most spirals and ULIRGs. We study the molecular medium at an angular resolution of 0.65 × 0.52 (∼120 × 98 pc) through our observations of 12CO 2−1 emission using the Submillimeter Array (SMA). We compare our 12CO 2−1 maps with the optical Hubble Space Telescope and high angular resolution radio continuum images to study the relationship between molecular gas and the other components of the starburst region. -
SAC's 110 Best of the NGC
SAC's 110 Best of the NGC by Paul Dickson Version: 1.4 | March 26, 1997 Copyright °c 1996, by Paul Dickson. All rights reserved If you purchased this book from Paul Dickson directly, please ignore this form. I already have most of this information. Why Should You Register This Book? Please register your copy of this book. I have done two book, SAC's 110 Best of the NGC and the Messier Logbook. In the works for late 1997 is a four volume set for the Herschel 400. q I am a beginner and I bought this book to get start with deep-sky observing. q I am an intermediate observer. I bought this book to observe these objects again. q I am an advance observer. I bought this book to add to my collect and/or re-observe these objects again. The book I'm registering is: q SAC's 110 Best of the NGC q Messier Logbook q I would like to purchase a copy of Herschel 400 book when it becomes available. Club Name: __________________________________________ Your Name: __________________________________________ Address: ____________________________________________ City: __________________ State: ____ Zip Code: _________ Mail this to: or E-mail it to: Paul Dickson 7714 N 36th Ave [email protected] Phoenix, AZ 85051-6401 After Observing the Messier Catalog, Try this Observing List: SAC's 110 Best of the NGC [email protected] http://www.seds.org/pub/info/newsletters/sacnews/html/sac.110.best.ngc.html SAC's 110 Best of the NGC is an observing list of some of the best objects after those in the Messier Catalog. -
Arxiv:Astro-Ph/0401239V1 13 Jan 2004
Paper status: Accepted to the ApJ Missing Massive Stars in Starbursts: Stellar Temperature Diagnostics and the IMF J. R. Rigby and G. H. Rieke Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 [email protected], [email protected] ABSTRACT Determining the properties of starbursts requires spectral diagnostics of their ultraviolet ra- diation fields, to test whether very massive stars are present. We test several such diagnostics, using new models of line ratio behavior combining Cloudy, Starburst99 and up-to-date spectral atlases (Pauldrach et al. 2001; Hillier & Miller 1998). For six galaxies we obtain new measure- ments of Hei 1.7 µm/Br10, a difficult to measure but physically simple (and therefore reliable) diagnostic. We obtain new measurements of Hei 2.06 µm/Brγ in five galaxies. We find that Hei 2.06 µm/Brγ and [Oiii]/Hβ are generally unreliable diagnostics in starbursts. The het- eronuclear and homonuclear mid–infrared line ratios (notably [Neiii] 15.6 µm / [Neii] 12.8 µm) consistently agree with each other and with Hei 1.7 µm/Br10; this argues that the mid–infrared line ratios are reliable diagnostics of spectral hardness. In a sample of 27 starbursts, [Neiii]/[Neii] is significantly lower than model predictions for a Salpeter IMF extending to 100 M⊙. Plausi- ble model alterations strengthen this conclusion. By contrast, the low–mass and low–metallicity galaxies II Zw 40 and NGC 5253 show relatively high neon line ratios, compatible with a Salpeter slope extending to at least ∼ 40–60 M⊙. One solution for the low neon line ratios in the high– metallicity starbursts would be that they are deficient in & 40 M⊙ stars compared to a Salpeter IMF. -
Gas Accretion from Minor Mergers in Local Spiral Galaxies⋆
A&A 567, A68 (2014) Astronomy DOI: 10.1051/0004-6361/201423596 & c ESO 2014 Astrophysics Gas accretion from minor mergers in local spiral galaxies? E. M. Di Teodoro1 and F. Fraternali1;2 1 Department of Physics and Astronomy, University of Bologna, 6/2, Viale Berti Pichat, 40127 Bologna, Italy e-mail: [email protected] 2 Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, The Netherlands Received 7 February 2014 / Accepted 28 May 2014 ABSTRACT We quantify the gas accretion rate from minor mergers onto star-forming galaxies in the local Universe using Hi observations of 148 nearby spiral galaxies (WHISP sample). We developed a dedicated code that iteratively analyses Hi data-cubes, finds dwarf gas-rich satellites around larger galaxies, and estimates an upper limit to the gas accretion rate. We found that 22% of the galaxies have at least one detected dwarf companion. We made the very stringent assumption that all satellites are going to merge in the shortest possible time, transferring all their gas to the main galaxies. This leads to an estimate of the maximum gas accretion rate of −1 0.28 M yr , about five times lower than the average star formation rate of the sample. Given the assumptions, our accretion rate is clearly an overestimate. Our result strongly suggests that minor mergers do not play a significant role in the total gas accretion budget in local galaxies. Key words. galaxies: interactions – galaxies: evolution – galaxies: kinematics and dynamics – galaxies: star formation – galaxies: dwarf 1. Introduction structures in the Universe grow by several inflowing events and have increased their mass content through a small number of The evolution of galaxies is strongly affected by their capabil- major mergers, more common at high redshifts, and through an ity of retaining their gas and accreting fresh material from the almost continuous infall of dwarf galaxies (Bond et al. -
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 -
Krips2005.Pdf (11.01Mb)
High Resolution Multi-Wavelength Study of Active Galaxies Inaugural-Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultat¨ der Universitat¨ zu Koln¨ vorgelegt von Melanie Krips aus Koln¨ Koln¨ 2005 Tag der mundlichen¨ Prufung:¨ 03.Februar 2005 1.Gutachter: Prof. Dr. Andreas Eckart 2.Gutachter: Prof. Dr. Claus Kiefer Meinen Eltern Abstract This PhD thesis presents a study of active galaxies carried out from cm- to mm-wavelengths with high angular resolution. The mechanism of the activity in these objects is supposed to be strongly correlated with the accretion of matter onto a super-massive black hole in their centres. One approach to increase the understanding of the nature of these highly interesting sources is to observe and analyse the molecular gas. The characteristics of its distribution and dynamics are indispensible diagnostic tools to investigate the accretion processes at different angular scales. A second approach can be found in the study of emission that originates in the direct vicinity of the black hole, such as non-thermal radio emission, for instance. To account for different activity levels, five objects were chosen ranging from nearby, Low Luminosity Active £¡ Galaxies (LLAGs; NGC 3718 at a redshift1 of ¢¡ 0.003 and NGC 1068 at 0.004) to higher redshifted, ¤¡ High Luminosity Active Galaxies (HLAGs; HE 1029-1831 at ¤¡ 0.039, 3C48 at 0.367, and Q0957+561 at ¥¡ 1.414). The first two sources are part of the so called NU(clei of)-GA(laxy) project, that aims at analysing the distribution and kinematics of the molecular gas at high angular resolution/sensitivity in a sample of in total 30 nearby LLAGs. -
Deprojecting Spiral Galaxies Using Fourier Analysis. Application to the Frei Sample?
A&A 415, 849–861 (2004) Astronomy DOI: 10.1051/0004-6361:20034186 & c ESO 2004 Astrophysics Deprojecting spiral galaxies using Fourier analysis. Application to the Frei sample? C. Barber`a1, E. Athanassoula2, and C. Garc´ıa-G´omez1 1 D.E.I.M., Campus Sescelades, Avd. dels Pa¨ısos Catalans 26, 43007 Tarragona, Spain 2 Observatoire de Marseille, 2 Place Le Verier, 13248 Marseille cedex 04, France Received 12 August 2003 / Accepted 30 September 2003 Abstract. We present two methods that can be used to deproject spirals, based on Fourier analysis of their images, and discuss their potential and restrictions. Our methods perform particularly well for galaxies more inclined than 50◦ or for non-barred galaxies more inclined than 35◦. They are fast and straightforward to use, and thus ideal for large samples of galaxies. Moreover, they are very robust for low resolutions and thus are appropriate for samples of cosmological interest. The relevant software is available from us upon request. We use these methods to determine the values of the position and inclination angles for a sample of 79 spiral galaxies contained in the Frei et al. (1996) sample. We compare our results with the values found in the literature, based on other methods. We find statistically very good agreement Key words. galaxies: structure – galaxies: spiral 1. Introduction while the IA is the angle between the perpendicular to the plane of the galaxy and the line of sight. Several methods have been Disc galaxies are observed projected on the sky. Yet for many proposed so far to obtain these angles, the most commonly used purposes one needs to be able to deproject them.