DOCSLIB.ORG

A Multi-Wavelength Study of Supernova Remnants in Six Nearby

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Multi-Wavelength Study of Supernova Remnants in Six Nearby Mon. Not. R. Astron. Soc. 000, 1–?? (2012) Printed 9 May 2018 (MN LATEX style file v2.2) A multiwavelength study of Supernova Remnants in six nearby galaxies. II. New optically selected Supernova Remnants I.Leonidaki,1,2⋆ P. Boumis,1⋆ A.Zezas3,4,5⋆ 1Institute of Astronomy, Astrophysics, Space Applications & Remote Sensing, National Observatory of Athens, I.Metaxa and V.Pavlou, Lofos Koufou, Penteli, 15236, Athens, Greece 2Astronomical Laboratory, Physics Department, University of Patras, 26500, Rio-Patra, Greece 3Physics Department, University of Crete, P.O. Box 2208, GR-710 03, Heraklion, Crete, Greece 4Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 5IESL/Foundation for Research and Technology-Hellas, P.O. Box 1527, GR-711 10, Heraklion, Crete, Greece ABSTRACT We present results from a study of optically emitting Supernova Remnants (SNRs) in six nearby galaxies (NGC2403, NGC3077, NGC4214, NGC4395, NGC4449 and NGC5204) based on deep narrow band Hα and [S II] images as well as spectroscopic observations. The SNR classification was based on the detected sources that fulfill the well-established emission line flux criterion of [S II]/Hα> 0.4. This study revealed ∼400 photometric SNRs down to a limiting Hα flux of 10−15 erg sec−1 cm−2. Spectroscopic observations confirmed the shock- excited nature of 56 out of the 96 sources with ([S II]/Hα)phot > 0.3 (our limit for an SNR classification) for which we obtained spectra. 11 more sources were spectroscopically identi- fied as SNRs although their photometric [S II]/Hα ratio was below 0.3. We discuss the prop- erties of the optically-detected SNRs in our sample for different types of galaxies and hence different environments, in order to address their connection with the surrounding interstellar medium. We find that there is a difference in [N II]/Hα line ratios of the SNR populations between different types of galaxies which indicates that this happens due to metallicity. We cross-correlate parameters of the optically detected SNRs ([S II]/Hα ratio, luminosity) with parameters of coincident X- ray emitting SNRs, resulted from our previousstudies in the same sample of galaxies, in order to understand their evolution and investigate possible selection effects. We do not find a correlation between their Hα and X-ray luminosities, which we at- tribute to the presence of material in a wide range of temperatures. We also find evidence for a linear relation between the number of luminous optical SNRs (1037 erg sec−1) and SFR in our sample of galaxies. arXiv:1211.6746v1 [astro-ph.CO] 28 Nov 2012 Key words: ISM: supernova remnants - galaxies: star formation 1 INTRODUCTION be used as proxies for measurements of massive star formation rate (SFR) and studies of stellar evolution (Condon & Yin 1990). Supernova Remnants (SNRs) inject the predominant fraction of mechanical energy that heats and shapes the Interstellar Medium Detecting large samples of SNRs in a multi-wavelength con- (ISM) since the generated shock waves are responsible for the com- text can provide several key aspects of the physical processes taking pression, acceleration and excitation of their surrounding medium. place during their evolution. For example, the blast waves of newly At the same time they replenish the ISM with heavy elements formed SNRs can heat the material behind the shock front to tem- formed during the evolution of massive stars while when immersed peratures up to 108 K producing thermal X-rays. Synchrotron radi- in molecular clouds the compression may trigger formation of the ation in radio wavelengths is produced at the vicinity of the shock next generation of stars. SNRs can yield significant information on as well as from the cooling regions behind the shock front, owing the global properties of a galaxy’s ISM such as its density, temper- to relativistic electrons gyrating in the magnetic field of the SNRs ature or composition (e.g. Blair & Long 2004). Furthermore, being (e.g. Dickel 1999; Charles & Seward 1995). Optical filaments are the endpoints of core-collapse massive stars (M > 8M⊙) they can signs of older SNRs since they form in the cooling regions behind the shock (i.e. Stupar & Parker 2009) producing shock-heated col- lisionally ionized species (such as [S II], [O III]orHα recombina- ⋆ E-mail: [email protected]; [email protected]; [email protected] tion lines). Therefore, multi-wavelength studies (optical, radio, X- c 2012 RAS 2 Leonidaki et al. rays, infrared) can surmount possible selection effects inherent in between the SNRs in spiral and irregular galaxies with the latter ’monochromatic’ samples of SNRs and provide a more complete tending to have flatter distributions. These results are presented in picture of their nature and evolution as well as their interplay with the first paper of this series (Leonidaki et al. 2010, hereafter Paper the ISM and their correlation with star forming activity. I). About 274 SNRs detected in different wavebands are known In this paper we present a detailed optical spectro-photometric in our Galaxy, a comprehensive catalogue of which is presented study of the SNR populations in this sample of galaxies. The op- in Green (2009). A large number of them has been studied in tical identification of SNRs is based on the elevated [S II]/Hα ra- detail in various wavebands (e.g. radio: Green 2009; optical: tio (> 0.4), pioneered by Mathewson & Clarke (1973). The outline Boumis et al. 2002, 2005, 2009; Fesen & Milisavljevic 2010; X- of this paper is as follows: In §2, we describe the observations, in- rays: Reynolds et al. 2009; Slane et al. 2002; infrared: Reach et al. cluding data reduction and techniques used for source detection and 2006) providing significant information on the properties of indi- photometry. In §3, we describe the long-slit and multi-slit spectro- vidual objects and SNR physics. However these studies are im- scopic observations, while in §4 we give the SNR classification cri- peded by distance uncertainties and Galactic absorption, hamper- teria as well as aggregate results of the detected SNRs in our sample ing the investigation of SNRs in a wide variety of environments. of galaxies. In §5 we discuss the results of our spectro-photometric On the other hand extragalactic studies of SNRs offer several ad- investigation. Finally, in §6 we present the conclusions of this work. vantages: they can be achieved in determined distances with much fewer observations while they cover a broader range of metallicities and ISM parameters than our Galaxy, giving us a more complete 2 IMAGING picture of the SNR population parameters. Numerous studies of extragalactic SNRs have been con- 2.1 Observations ducted since the pioneering work of Mathewson & Clarke (1973) Optical images were obtained with the 1.3m (f/7.7) Ritchey– on the Magellanic Clouds. The availability of sensitive, high- Chr´etien telescope at Skinakas Observatory on June 6-12, 2008 resolution observations in the radio and X-ray bands have allowed and Nov 16-18, 2009. A 2048 × 2048 ANDOR Tech CCD was ′ ′ the systematic investigation of extragalactic SNRs in these wave- used which has a 9.6 × 9.6 field of view and an image scale of bands (e.g. Leonidaki et al. 2010; Long et al. 2010; Pannuti et al. 0.28′′ per pixel. Apart from Nov 18 2009, all the other observing 2007; Ghavamian et al. 2005). However, since the first studies in nights were photometric with seeing conditions ranging between a small sample of nearby galaxies (e.g. Matonick & Fesen 1997; 1.3′′-2.5′′. The observations were performed with the narrow band Matonick et al. 1997) there have not been any systematic pursuits Hα + [N II], [S II] and [O III] filters. Broadband continuum filters of the optical populations of extragalactic SNRs. in red and blue were used to subtract the continuum from the Hα+ The availability of sensitive wide-field imagers and spectro- [N II], [S II] and [O III] images respectively. The continuum filters graphs allow us to greatly extend these initial efforts to a larger used for the observations are centered on line-free regions of the set of galaxies, while probing fainter SNRs populations. We have spectra in order to avoid strong SNR emission lines to pass. The embarked in an extensive multi-wavelength investigation of the interference filter characteristics are listed in Table 2. SNR populations in six nearby galaxies (NGC 2403, NGC 3077, The exposure time was 3600 sec for each Hα + [N II] filter ex- NGC 4214, NGC 4395, NGC 4449 and NGC 5204), involving op- posure, 7200 sec for each [S II] filter exposure and 300 sec for the tical and X-ray data. These galaxies are selected from the Third exposures through the continuum filters. The airmass of the galax- Catalog of Bright Galaxies (RC3; de Vaucouleurs et al. 1995) to be ies during observations ranged between 1.06 and 1.87. In the case (a) late type (T > 4; Hubble type), (b) close (65 Mpc) in order to 9 6′ ◦ of NGC 2403, the . CCD field of view did not cover the whole minimize source confusion, (c) at low inclination 6 60 ) in order 1 D25 area of the galaxy, therefore we obtained a 2×2 mosaic. We to minimize internal extinction and projection effects, and (d) be did not observe NGC 2403 and NGC 4395 through [O III] or contin- 20◦ above the Galactic plane (|b| > ). The properties of the galaxies uum blue filters owing to weather conditions. Bias frames and well- in our sample are presented in Table 1 while a list of previous multi- exposed twilight flats were taken on each run as well as spectro- wavelength SNR surveys are presented in §2 of Leonidaki et al.
Load more

Recommended publications
  • The Suzaku Broadband X-Ray Spectrum of the Dwarf Seyfert Galaxy NGC 4395 K
    A&A 514, A58 (2010) Astronomy DOI: 10.1051/0004-6361/200912431 & c ESO 2010 Astrophysics The Suzaku broadband X-ray spectrum of the dwarf Seyfert galaxy NGC 4395 K. Iwasawa1,, Y. Tanaka2, and L. C. Gallo3 1 INAF-Ossservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy e-mail: [email protected] 2 Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, 85748 Garching, Germany e-mail: [email protected] 3 Department of Astronomy and Physics, Saint Mary’s University, Halifax, NS B3H 3C3, Canada e-mail: [email protected] Received 6 May 2009 / Accepted 21 December 2009 ABSTRACT 5 We present a Suzaku observation of the dwarf Seyfert galaxy NGC 4395 with an estimated black hole mass of ∼10 M. Rapid and strong X-ray variability with an rms amplitude of ∼60 per cent is observed in the 0.4–10 keV band with the XIS cameras. The shape of the light curve appears to depend on energies. The hard X-ray emission is detected up to 35 keV with the HXD-PIN detector at a similar flux level as observed with the INTEGRAL IBIS. The X-ray spectrum below 10 keV is strongly absorbed by partially ionized (ξ ∼ 35 erg s cm−1) gas with a mean equivalent hydrogen column density of ∼2 × 1022 cm−2, when a simple absorption model is applied. The spectral shape is also strongly variable but not a simple function of the source brightness. The spectral variability appears to be accounted for mainly by continuum slope changes, but variability in the ionized absorber may also play some part.
    [Show full text]
  • Torus Model Properties of an Ultra-Hard X-Ray Selected Sample of Seyfert Galaxies.', Monthly Notices of the Royal Astronomical Society., 486 (4)
    Durham Research Online Deposited in DRO: 16 July 2019 Version of attached le: Published Version Peer-review status of attached le: Peer-reviewed Citation for published item: Garc¡a-Bernete,I. and RamosAlmeida, C. and Alonso-Herrero, A. and Ward, M. J. and Acosta-Pulido, J. A. and Pereira-Santaella, M. and Hern¡an-Caballero,A. and AsensioRamos, A. and Gonz¡alez-Mart¡n,O. and Levenson, N. A. and Mateos, S. and Carrera, F. J. and Ricci, C. and Roche, P. and Marquez, I. and Packham, C. and Masegosa, J. and Fuller, L. (2019) 'Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies.', Monthly notices of the Royal Astronomical Society., 486 (4). pp. 4917-4935. Further information on publisher's website: https://doi.org/10.1093/mnras/stz1003 Publisher's copyright statement: c 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. Additional information: Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom Tel : +44 (0)191 334 3042 | Fax : +44 (0)191 334 2971 https://dro.dur.ac.uk MNRAS 486, 4917–4935 (2019) doi:10.1093/mnras/stz1003 Advance Access publication 2019 April 10 Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies I.
    [Show full text]
  • Synapses of Active Galactic Nuclei: Comparing X-Ray and Optical Classifications Using Artificial Neural Networks?
    A&A 567, A92 (2014) Astronomy DOI: 10.1051/0004-6361/201322592 & c ESO 2014 Astrophysics Synapses of active galactic nuclei: Comparing X-ray and optical classifications using artificial neural networks? O. González-Martín1;2;??, D. Díaz-González3, J. A. Acosta-Pulido1;2, J. Masegosa4, I. E. Papadakis5;6, J. M. Rodríguez-Espinosa1;2, I. Márquez4, and L. Hernández-García4 1 Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n, 38205 La Laguna, Spain e-mail: [email protected] 2 Departamento de Astrofísica, Universidad de La Laguna (ULL), 38205 La Laguna, Spain 3 Shidix Technologies, 38320, La Laguna, Spain 4 Instituto de Astrofísica de Andalucía, CSIC, C/ Glorieta de la Astronomía s/n, 18005 Granada, Spain 5 Physics Department, University of Crete, PO Box 2208, 710 03 Heraklion, Crete, Greece 6 IESL, Foundation for Research and Technology, 711 10 Heraklion, Crete, Greece Received 2 September 2013 / Accepted 3 April 2014 ABSTRACT Context. Many classes of active galactic nuclei (AGN) have been defined entirely through optical wavelengths, while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many discrepancies that have not been fully understood yet. Aims. The main purpose of the present paper is to study the synapses (i.e., connections) between X-ray and optical AGN classifications. Methods. For the first time, the newly implemented efluxer task allowed us to analyse broad band X-ray spectra of a sample of emission-line nuclei without any prior spectral fitting. Our sample comprises 162 spectra observed with XMM-Newton/pn of 90 lo- cal emission line nuclei in the Palomar sample.
    [Show full text]
  • Pos(10Th EVN Symposium)081 ]), We Have Targeted a Few Additional 3 ∗ [email protected] [email protected] Speaker
    More discoveries of compact radio cores in Seyfert galaxies with the EVN PoS(10th EVN Symposium)081 Marcello Giroletti∗ INAF Istituto di Radioastronomia via Gobetti 101, 40129 Bologna (Italy) E-mail: [email protected] Francesca Panessa INAF IASF, via Fosso del Cavaliere 100, 00133 Rome, Italy E-mail: [email protected] Following the high detection rate achieved by EVN observations of the central regions of local Seyfert galaxies (Giroletti & Panessa 2009, ApJL 706, 260, [3]), we have targeted a few additional sources from a complete sample. We have detected three more sources (NGC 3982, NGC 3227, and NGC 4138) at both 1.6 and 5 GHz and present preliminary results. Moreover, the declination of the sources was suitable to include Arecibo in the EVN observations, which provides important clues on the compactness of the emission region. 10th European VLBI Network Symposium and EVN Users Meeting: VLBI and the new generation of radio arrays September 20-24, 2010 Manchester Uk ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ More discoveries of compact radio cores in Seyfert galaxies with the EVN Marcello Giroletti PoS(10th EVN Symposium)081 Figure 1: Combined optical and EVN images of Seyfert galaxies. Clockwise from top left: NGC 4051, NGC 4388, NGC 5033, and NGC 4501. Optical images from Sloan Digital Sky Survey, radio ones from EVN observations at 1.6 GHz ([3], typical beam 10 × 5 mas). 1. Background: recent VLBI observations of local Seyfert galaxies It is a well established fact that radio quiet Active Galactic Nuclei (AGNs) are not radio silent: indeed, VLA observations reveal emission at milliJansky level in most AGNs, even in low- luminosity AGNs [5].
    [Show full text]
  • A 10000-Solar-Mass Black Hole in the Nucleus of a Bulgeless Dwarf Galaxy
    A 10,000-solar-mass black hole in the nucleus of a bulge- less dwarf galaxy Jong-Hak Woo1, Hojin Cho1, Elena Gallo2, Edmund Hodges-Kluck2;3;4, Huynh Anh Le1, Jaejin Shin1, Donghoon Son1, & John C. Horst5 1Department of Physics & Astronomy, Seoul National University, Seoul, 08826, Republic of Korea 2Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA 3Department of Astronomy, University of Maryland, College Park, MD 20742, USA 4NASA/GSFC, Code 662, Greenbelt, MD 20771, USA 5San Diego State University, San Diego, CA 92182, USA The motions of gas and stars in the nuclei of nearby large galaxies have demonstrated that massive black holes are common1 and that their masses strongly correlate with the stellar 2;3;4 velocity dispersion σ? of the bulge . This correlation suggests that massive black holes and galaxies influence each other’s growth5;6;7. Dynamical measurements are less reliable when the sphere of influence is unresolved, thus it remains unknown whether this correlation exists in galaxies much smaller than the Milky Way, as well as what fraction of these galaxies have central black holes. Light echoes from photoionized clouds around accreting black 8;9 arXiv:1905.00145v2 [astro-ph.GA] 13 Jun 2019 holes , in combination with the velocity of these clouds, yield a direct mass measurement that circumvents this difficulty. Here we report an exceptionally low reverberation delay of 83 14 minutes between variability in the accretion disk and high velocity Hα emission from ± the nucleus of the bulgeless dwarf galaxy NGC 4395. Combined with the Hα line-of-sight 1 −1 velocity dispersion σ = 426 1 km s , this lag determines a mass of about 10,000 M for line ± the black hole.
    [Show full text]
  • The Exceptional X-Ray Variability of the Dwarf Seyfert Nucleus NGC 4395 S
    Mon. Not. R. Astron. Soc. 356, 524–530 (2005) doi:10.1111/j.1365-2966.2004.08463.x The exceptional X-ray variability of the dwarf Seyfert nucleus NGC 4395 S. Vaughan,1 K. Iwasawa,2 A. C. Fabian2 and K. Hayashida3 1X-Ray and Observational Astronomy Group, University of Leicester, Leicester LE1 7RH 2Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA 3Department of Earth and Space Science, Osaka University, Osaka 560-0043, Japan Accepted 2004 September 30. Received 2004 September 29; in original form 2004 July 2 Downloaded from https://academic.oup.com/mnras/article/356/2/524/1156268 by guest on 24 September 2021 ABSTRACT An analysis of the X-ray variability of the low-luminosity Seyfert nucleus NGC 4395, based on a long XMM–Newton observation, is presented. The power spectrum shows a clear break from a flat spectrum (α ≈ 1) to a steeper spectrum (α ≈ 2) at a frequency f br = 0.5– 3.0 × 10−3 Hz, comparable to the highest characteristic frequency found previously in a Seyfert galaxy. This extends the measured M BH − f br values to lower MBH than previous studies of Seyfert galaxies, and is consistent with an inverse scaling of variability frequency with black hole mass. The variations observed are among the most violent seen in an active galactic nuclei to date, with the fractional rms amplitude (Fvar)exceeding 100 per cent in the softest band. The amplitude of the variations seems intrinsically higher in NGC 4395 than most other Seyfert galaxies, even after accounting for the differences in characteristic frequencies.
    [Show full text]
  • Infrared Signature of Active Massive Black Holes in Nearby Dwarf Galaxies? Francine R
    A&A 602, A28 (2017) Astronomy DOI: 10.1051/0004-6361/201629832 & c ESO 2017 Astrophysics Infrared signature of active massive black holes in nearby dwarf galaxies? Francine R. Marleau1, Dominic Clancy1, Rebecca Habas1, and Matteo Bianconi1; 2 1 Institute of Astro and Particle Physics, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria e-mail: [Francine.Marleau;Dominic.Clancy;Rebecca.Habas]@uibk.ac.at 2 Astrophysics and Space Research Group, School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK Received 3 October 2016 / Accepted 28 March 2017 ABSTRACT Context. We investigate the possible presence of active galactic nuclei (AGN) in dwarf galaxies and other nearby galaxies to identify candidates for follow-up confirmation and dynamical mass measurements. Aims. We identify candidate active central massive black holes (CMBH) using their mid-infrared emission, verify their nature using existing catalogues and optical line emission diagnostics, and study the relationship between their mass and the mass of their host galaxy. Methods. We use the Wide-field Infrared Survey Explorer (WISE) All-Sky Release Source Catalog and examine the infrared colours of a sample of dwarf galaxies and other nearby galaxies in order to identify both unobscured and obscured candidate AGN by applying the infrared colour diagnostic. Stellar masses of galaxies are obtained using a combination of three independent methods. Black hole masses are estimated using the bolometric luminosity of the AGN candidates and computed for three cases of the bolometric-to- Eddington luminosity ratio. Results. We identify 303 candidate AGN, of which 276 were subsequently found to have been independently identified as AGN via other methods.
    [Show full text]
  • X-Ray Spectral Survey with XMM–Newton of a Complete Sample of Nearby Seyfert Galaxies
    A&A 446, 459–470 (2006) Astronomy DOI: 10.1051/0004-6361:20053893 & c ESO 2006 Astrophysics X-ray spectral survey with XMM–Newton of a complete sample of nearby Seyfert galaxies M. Cappi1, F. Panessa2, L. Bassani1,M.Dadina1, G. DiCocco1, A. Comastri3, R. Della Ceca4, A. V. Filippenko5, F. Gianotti1,L.C.Ho6, G. Malaguti1,J.S.Mulchaey6,G.G.C.Palumbo7, E. Piconcelli8,W.L.W.Sargent9, J. Stephen1, M. Trifoglio1, and K. A. Weaver10 1 INAF-IASF Sezione di Bologna, via Gobetti 101, 40129 Bologna, Italy e-mail: [email protected] 2 Instituto de Fisica de Cantabria (CSIC-UC), Avda de los Castros, 39005 Santander, Spain 3 INAF- Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy 4 INAF- Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano, Italy 5 Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA 6 Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101, USA 7 Dipartimento di Astronomia, Universita’ degli Studi di Bologna, via Ranzani 1, 40127 Bologna, Italy 8 XMM–Newton Science Operation Center/RSSD-ESA, Apartado 50727, 28080 Madrid, Spain 9 Department of Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 10 Laboratory for High Energy Astrophysics, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771, USA Received 23 July 2005 / Accepted 28 September 2005 ABSTRACT Results obtained from an X-ray spectral survey of nearby Seyfert galaxies using XMM–Newton are reported. The sample was optically selected, well defined, complete in B magnitude, and distance limited: it consists of the nearest (D ∼< 22 Mpc) 27 Seyfert galaxies (9 of type 1, 18 of type 2) taken from the Ho et al.
    [Show full text]
  • X-Ray Nature of the LINER Nuclear Sources O
    A&A 460, 45–57 (2006) Astronomy DOI: 10.1051/0004-6361:20054756 & c ESO 2006 Astrophysics X-ray nature of the LINER nuclear sources O. González-Martín1, J. Masegosa1, I. Márquez1,M.A.Guerrero1, and D. Dultzin-Hacyan2 1 Instituto de Astrofísica de Andalucía, CSIC, Apartado Postal 3004, 18080 Granada, Spain e-mail: [email protected] 2 Instituto de Astronomía, UNAM, Apartado Postal 70-264, 04510 México D.F., México Received 22 December 2005 / Accepted 17 May 2006 ABSTRACT We report the results from a homogeneous analysis of the X-ray (Chandra ACIS) data available for a sample of 51 LINER galaxies selected from the catalogue by Carrillo et al. (1999, Rev. Mex. Astron. Astrofis., 35, 187) and representative of the population of bright LINER sources. The nuclear X-ray morphology has been classified by their nuclear compactness in the hard band (4.5– 8.0 keV) into 2 categories: active galactic nuclei (AGN) candidates (with a clearly identified unresolved nuclear source) and starburst (SB) candidates (without a clear nuclear source). Sixty percent of the total sample are classified as AGNs, with a median luminosity 40 −1 of LX(2−10 keV) = 2.5 × 10 erg s , which is an order of magnitude higher than for SB-like nuclei. The spectral fitting allows us to conclude that most of the objects need a non-negligible power-law contribution. When no spectral fitting can be performed (data with a low signal-to-noise ratio), the color–color diagrams allow us to roughly estimate physical parameters, such as column density, temperature of the thermal model, or spectral index for a power-law, and therefore to better constrain the origin of the X-ray emission.
    [Show full text]
  • Galaxy Flow in the Canes Venatici I Cloud
    Astronomy & Astrophysics manuscript no. IKarachentsev November 2, 2018 (DOI: will be inserted by hand later) Galaxy Flow in the Canes Venatici I Cloud ⋆ I. D. Karachentsev1, M. E. Sharina1,10, A. E. Dolphin2, E. K. Grebel3, D. Geisler4, P. Guhathakurta5, P. W. Hodge6, V. E. Karachentseva7, A. Sarajedini8, and P. Seitzer9 1 Special Astrophysical Observatory, Russian Academy of Sciences, N. Arkhyz, KChR, 369167, Russia 2 Kitt Peak National Observatory, National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726, USA 3 Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, D-69117 Heidelberg, Germany 4 Departamento de F´ısica, Grupo de Astronom´ıa, Universidad de Concepci´on, Casilla 160-C, Concepci´on, Chile 5 UCO/Lick Observatory, University of California at Santa Cruz, Santa Cruz, CA 95064, USA 6 Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA 7 Astronomical Observatory of Kiev University, 04053, Observatorna 3, Kiev, Ukraine 8 Department of Astronomy, University of Florida, Gainesville, FL 32611, USA 9 Department of Astronomy, University of Michigan, 830 Dennison Building, Ann Arbor, MI 48109, USA 10 Isaac Newton Institute, Chile, SAO Branch arXiv:astro-ph/0210414v1 18 Oct 2002 Received: August 8, 2002 Abstract. We present an analysis of Hubble Space Telescope/WFPC2 images of eighteen galaxies in the Canes Venatici I cloud. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ∼ 12 %. The resulting distances are 3.9 Mpc (UGC 6541), 4.9 Mpc (NGC 3738), 3.0 Mpc (NGC 3741), 4.5 Mpc (KK 109), > 6.3 Mpc (NGC 4150), 4.2 Mpc (UGC 7298), 4.5 Mpc (NGC 4244), 4.6 Mpc (NGC 4395), 4.9 Mpc (UGC 7559), 4.2 Mpc (NGC 4449), 4.4 Mpc (UGC 7605), 4.6 Mpc (IC 3687), 4.7 Mpc (KK 166), 4.7 Mpc (NGC 4736), 4.2 Mpc (UGC 8308), 4.3 Mpc (UGC 8320), 4.6 Mpc (NGC 5204), and 3.2 Mpc (UGC 8833).
    [Show full text]
  • THE STRUCTURE of NUCLEAR STAR CLUSTERS in NEARBY LATE-TYPE SPIRAL GALAXIES from HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 IMAGING* Daniel J
    The Astronomical Journal, 149:170 (21pp), 2015 May doi:10.1088/0004-6256/149/5/170 © 2015. The American Astronomical Society. All rights reserved. THE STRUCTURE OF NUCLEAR STAR CLUSTERS IN NEARBY LATE-TYPE SPIRAL GALAXIES FROM HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 IMAGING* Daniel J. Carson1, Aaron J. Barth1, Anil C. Seth2, Mark den Brok2, Michele Cappellari3, Jenny E. Greene4, Luis C. Ho5,6, and Nadine Neumayer7 1 Department of Physics and Astronomy, University of California Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697, USA 2 Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA 3 Sub-Department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK 4 Department of Astrophysical Sciences, Princeton University, Peyton Hall—Ivy Lane, Princeton, NJ 08544, USA 5 Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China 6 Department of Astronomy, School of Physics, Peking University, Beijing 100871, China 7 Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany Received 2014 November 1; accepted 2015 January 20; published 2015 April 28 ABSTRACT We obtained Hubble Space Telescope/Wide Field Camera 3 imaging of a sample of ten of the nearest and brightest nuclear clusters (NCs) residing in late-type spiral galaxies, in seven bands that span the near-UV to the near-IR. Structural properties of the clusters were measured by fitting two-dimensional surface brightness profiles to the images using GALFIT. The clusters exhibit a wide range of structural properties, with F814W absolute magnitudes that range from −11.2 to −15.1 mag and F814W effective radii that range from 1.4 to 8.3 pc.
    [Show full text]
  • The Structure & Stellar Populations of Nuclear Star Clusters in Late-Type
    UC Irvine UC Irvine Electronic Theses and Dissertations Title The Structure and Stellar Populations of Nuclear Star Clusters in Late-Type Spiral Galaxies Permalink https://escholarship.org/uc/item/3634g66n Author Carson, Daniel James Publication Date 2016 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, IRVINE The Structure & Stellar Populations of Nuclear Star Clusters in Late-Type Spiral Galaxies DISSERTATION submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in Physics by Daniel J. Carson Dissertation Committee: Professor Aaron Barth, Chair Associate Professor Michael Cooper Professor James Bullock 2016 Portion of Chapter 1 c 2015 The Astronomical Journal Chapter 2 c 2015 The Astronomical Journal Chapter 3 c 2015 The Astronomical Journal Portion of Chapter 5 c 2015 The Astronomical Journal All other materials c 2016 Daniel J. Carson TABLE OF CONTENTS Page LIST OF FIGURES iv LIST OF TABLES vi ACKNOWLEDGMENTS vii CURRICULUM VITAE viii ABSTRACT OF THE DISSERTATION x 1 Introduction 1 2 HST /WFC3 data 9 2.1 SampleSelection ................................. 9 2.2 DescriptionofObservations . 10 2.3 DataReduction.................................. 14 3 Analysis of Structural Properties 17 3.1 Surface Brightness Profile Fitting . 17 3.1.1 PSFModels................................ 18 3.1.2 FittingMethod .............................. 19 3.1.3 Comparison with ISHAPE ......................... 21 3.1.4 1DRadialProfiles ............................ 22 3.1.5 Uncertainties in Cluster Parameters . 25 3.2 Results....................................... 29 3.2.1 SingleBandResults ........................... 29 3.2.2 PanchromaticResults........................... 40 3.2.3 Stellar Populations . 46 3.3 CommentsonIndividualObjects . 51 3.3.1 IC342................................... 51 3.3.2 M33 ...................................
    [Show full text]