DOCSLIB.ORG

A Quintet of Black Hole Mass Determinations1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Quintet of Black Hole Mass Determinations1 DRAFT VERSION OCTOBER 25, 2018 Preprint typeset using LATEX style emulateapj v. 08/22/09 A QUINTET OF BLACK HOLE MASS DETERMINATIONS1 KAYHAN GULTEKIN¨ 2,DOUGLAS O. RICHSTONE2,KARL GEBHARDT3,TOD R. LAUER4,JASON PINKNEY5, M. C. ALLER6,RALF BENDER7,ALAN DRESSLER8, S. M. FABER9,ALEXEI V. FILIPPENKO10,RICHARD GREEN11,LUIS C. HO8,JOHN KORMENDY3, CHRISTOS SIOPIS12 Draft version October 25, 2018 ABSTRACT We report five new measurements of central black hole masses based on STIS and WFPC2 observations with the Hubble Space Telescope and on axisymmetric, three-integral, Schwarzschild orbit-library kinematic models. We selected a sample of galaxies within a narrow range in velocity dispersion that cover a range of galaxy parameters (including Hubble type and core/power-law surface density profile) where we expected to be able to resolve the galaxy’s sphere of influence based on the predicted value of the black hole mass from the +1:5 8 M–s relation. We find masses for the following galaxies: NGC 3585, MBH = 3:4−0:6 × 10 M ; NGC 3607, +0:4 8 +0:7 8 +0:3 8 MBH = 1:2−0:4 × 10 M ; NGC 4026, MBH = 2:1−0:4 × 10 M ; and NGC 5576, MBH = 1:8−0:4 × 10 M , +17 6 all significantly excluding MBH = 0. For NGC 3945, MBH = 9−21 × 10 M , which is significantly below predictions from M–s and M–L relations and consistent with MBH = 0, though the presence of a double bar in this galaxy may present problems for our axisymmetric code. Subject headings: black hole physics — galaxies: general — galaxies:nuclei — stellar dynamics 1. INTRODUCTION TO BLACK HOLE MASS MEASUREMENTS have also been derived from stellar proper motions in our This paper is the latest in a campaign to model the cen- Galaxy (Genzel et al. 2000; Ghez et al. 2005), from mega- tral regions of galaxies to determine masses of putative black maser measurements of gas disks around central black holes holes from images and spectra taken with the Hubble Space (e.g., Miyoshi et al. 1995), and from gas velocity measure- Telescope (HST). The discovery of the presence of a massive ments (e.g., Barth et al. 2001). Reverberation mapping has dark object (probably a black hole) in almost all galaxies hav- also been used to find virial products in variable active galac- ing bulges, and the scaling relations found versus host-galaxy tic nuclei (AGNs; e.g., Peterson et al. 2004). properties, will stand as one of the important legacies of this Direct dynamical masses are the foundation for all scal- great observatory. ing relations used to infer black hole masses in active galax- Masses were first determined from stellar velocity mea- ies; all measures of black hole mass are derived from the di- surements made with ground-based telescopes having the best rect, dynamical measurements. Indirect mass indicators, such possible spatial resolution, together with isotropic kinematic as AGN line widths, are calibrated to reverberation mapping models (Dressler & Richstone 1988). When combined with measurements (Bentz et al. 2006), which are themselves nor- the spatial resolution of HST, this method has become the malized against the direct dynamical measurements (Onken standard for black hole mass measurements (e.g., van der et al. 2004). Marel et al. 1998; Gebhardt et al. 2000b). Black hole masses A central goal of a companion paper (Gultekin¨ et al. 2009) is the accurate measurement of the intrinsic or cosmic scat- 1 Based on observations made with the Hubble Space Telescope, obtained ter in the M–s and M-L relationships (Magorrian et al. 1998; at the Space Telescope Science Institute, which is operated by the Associa- Gebhardt et al. 2000a). We have thus chosen to augment the tion of Universities for Research in Astronomy, Inc., under NASA contract existing sample of MBH measurements with new determina- NAS 5-26555. These observations are associated with GO proposals 5999, tions of M for five galaxies selected to fall within a narrow 6587, 6633, 7468, and 9107. BH 2 Department of Astronomy, University of Michigan, Ann Arbor, MI, range in velocity dispersion. Along with results from the lit- 48109; Send correspondence to [email protected]. erature, this provides a number of galaxies in a narrow range arXiv:0901.4162v2 [astro-ph.GA] 1 May 2009 3 Department of Astronomy, University of Texas, Austin, TX, 78712. in velocity dispersion large enough that we may probe the in- 4 National Optical Astronomy Observatory, Tucson, AZ 85726. trinsic scatter in the relation without biases incurred by, for 5 Department of Physics and Astronomy, Ohio Northern University, Ada, example, looking only at residuals to power-law fits. OH 45810. 6 Department of Physics, Institute of Astronomy, ETH Zurich, CH-8093 We present observations of the centers of five early-type Zurich, Switzerland. galaxies in x 2, including HST observations in x 2.3, ground- 7 Universitaets-Sternwarte der Ludwig-Maximilians-Universitat,¨ Schein- based imaging in x 2.4, and ground-based spectra in x 2.5. We erstr. 1, D-81679 Munchen,¨ Germany. report results of dynamical models and black hole masses in 8 Observatories of the Carnegie Institution of Washington, Pasadena, CA x 3, and summarize in x 4. In the Appendix, we provide our 91101. 9 University of California Observatories/Lick Observatory, Board of Stud- data tables. ies in Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064. M 10 Department of Astronomy, University of California, Berkeley, CA 2. OBSERVATIONS FOR NEW BH DETERMINATIONS 94720-3411. 2.1. Observational Sample 11 LBT Observatory, University of Arizona, Tucson, AZ 85721. 12 Institut d’Astronomie et d’Astrophysique, Universite´ Libre de Brux- The five galaxies in this study were selected to come from a elles, B-1050 Bruxelles, Belgium. narrow range in velocity dispersion (180 < s < 200 km s−1) 2 Gultekin¨ et al. based on HyperLEDA13 central velocity dispersion measures 234). Reciprocal dispersion measured using our own wave- (Paturel et al. 2003). We chose this range because (1) it in- length solutions was 0.554 A˚ pixel−1. The distribution of dis- cludes galaxies with MB ≈ −20 mag where both core and persion solutions for a given data set had a s ≈ 1:5 × 10−4 power-law surface-brightness profiles exist and (2) it includes A˚ pixel−1. The average dispersion given in the Handbook for both late- and early-type galaxies. We selected galaxies with G750M is 0.56 A˚ pixel−1. We found a comparison line width distances such that the predicted radius of influence was larger ˚ −1 than 0:001. The radius of influence is defined as of s = 0:45 A = 17:5 km s . Instrumental line widths were measured by fitting Gaussians to emission lines on compari- GMBH son lamp exposures. This gives an estimate of the instrumen- Rinfl ≡ 2 ; (1) s (Rinfl) tal line width for extended sources. We use approximately five lines per exposure, and at least five measurements per where the velocity dispersion s is evaluated at the radius of line. While the comparison lamp exposures were unbinned, influence. This obviously requires an iterative solution, but it the galaxy spectra were binned, which increases the measured converges quickly. The predicted mass comes from the central widths by ∼25% for the 0:001 slit and by ∼ 3% for the 0:002 slit velocity dispersion measurement and the M–s fit of Tremaine at 8561 A.˚ Leitherer et al. (2001, p. 300) give the follow- et al.(2002). ing instrumental line widths for point sources: s=13.3, 15.0, The sample of new galaxies and their properties are pre- 16.7 km s−1 for the first three G750M setups in Table2. The sented in Table1. Distances are calculated assuming a Hubble 00 −1 −1 −1 spatial scale is 0: 05597 pixel for G750M at 8561 A.˚ constant of H0 = 70 km s Mpc . We also provide “Nuker Law” surface-brightness profile parameters as a function of The STIS data reduction was done with our own programs radius given by and FITSIO subroutines (Pence 1998; Pinkney et al. 2003). The raw spectra were extracted from the multidimensional (g−b)=a r g r a FITS file, and a constant fit was subtracted from the over- I (r) = 2(b−g)=aI b 1 + ; (2) scan region to remove the bias level. Because the STIS CCD b r r b has warm and hot pixels that evolve on timescales of . 1 d, which is a broken power-law profile (Lauer et al. 1995). In the dark-current subtraction needs to be accurate. We used addition to the five galaxies whose black hole masses are re- the iterative self-dark method described by Pinkney et al. ported in this paper, we observed five others with HST as part (2003). After flat fielding, we vertically shifted the spectra of the same observing proposal. Two of these (NGC 1374 and to a common dither, combined them, and then rotated. One- NGC 7213) had very low signal-to-noise ratio (S/N). The re- dimensional spectra were extracted from the final spectro- maining three (NGC 2434, NGC 4382, and NGC 7727) will gram using a biweight combination of rows. A 1-pixel wide be presented in a future paper. binning scheme was used near the galaxy center to optimize spatial resolution. We present Gauss–Hermite moments of the 2.2. WFPC2 Imaging velocity profiles in the Appendix. The high-resolution photometry of the central regions of Ground-Based Imaging the galaxies comes from Wide Field Planetary Camera 2 2.4. (WFPC2) observations on HST using filters F555W (V) and CCD images of one of our galaxies, NGC 3945, were ob- F814W (I).
Load more

Recommended publications
  • Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange
    Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange Atlas Karte (2000.0) Kulmination um Cambridge 10, 16, Mitternacht: Star Atlas 17 12, 13, Sky Atlas Benachbarte Sternbilder: 20, 21 Ant Cnc Cen Crv Crt Leo Lib 9. Februar Lup Mon Pup Pyx Sex Vir Deklinationsbereic h: -35° ... 7° Fläche am Himmel: 1303° 2 Mythologie und Geschichte: Bei der nördlichen Wasserschlange überlagern sich zwei verschiedene Bilder aus der griechischen Mythologie. Das erste Bild zeugt von der eher harmlosen Wasserschlange aus der Geschichte des Raben : Der Rabe wurde von Apollon ausgesandt, um mit einem goldenen Becher frisches Quellwasser zu holen. Stattdessen tat sich dieser an Feigen gütlich und trug bei seiner Rückkehr die Wasserschlange in seinen Fängen, als angebliche Begründung für seine Verspätung. Um jedermann an diese Untat zu erinnern, wurden der Rabe samt Becher und Wasserschlange am Himmel zur Schau gestellt. Von einem ganz anderen Schlag war die Wasserschlange, mit der Herakles zu tun hatte: In einem Sumpf in der Nähe von Lerna, einem See und einer Stadt an der Küste von Argo, hauste ein unsagbar gefährliches und grässliches Untier. Diese Schlange soll mehrere Köpfe gehabt haben. Fünf sollen es gewesen sein, aber manche sprechen auch von sechs, neun, ja fünfzig oder hundert Köpfen, aber in jedem Falle war der Kopf in der Mitte unverwundbar. Fürchterlich war es, da diesen grässlichen Mäulern - ob die Schlange nun schlief oder wachte - ein fauliger Atem, ein Hauch entwich, dessen Gift tödlich war. Kaum schlug ein todesmutiger Mann dem Untier einen Kopf ab, wuchsen auf der Stelle zwei neue Häupter hervor, die noch furchterregender waren. Eurystheus, der König von Argos, beauftragte Herakles in seiner zweiten Aufgabe diese lernäische Wasserschlange zu töten.
    [Show full text]
  • Extending the M (Bh)-Sigma Diagram with Dense Nuclear Star Clusters
    Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 11 November 2018 (MN LATEX style file v2.2) Extending the Mbh–σ diagram with dense nuclear star clusters Alister W. Graham1⋆, 1 Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia. Submitted 08 Aug, 2011 ABSTRACT Four new nuclear star cluster masses, Mnc, plus seven upper limits, are provided for galaxies with previously determined black hole masses, Mbh. Together with a sample of 64 galaxies with direct Mbh measurements, 13 of which additionally now have Mnc measurements rather than only upper limits, plus an additional 29 dwarf galaxies with available Mnc measurements and velocity dispersions σ, an (Mbh + Mnc)–σ diagram is constructed. Given that major dry galaxy merger events preserve the Mbh/L ratio, and given that L ∝ σ5 for luminous galaxies, it is first noted that the observation 5 Mbh ∝ σ is consistent with expectations. For the fainter elliptical galaxies it is known 2 that L ∝ σ , and assuming a constant Mnc/L ratio (Ferrarese et al.), the expectation 2 that Mnc ∝ σ is in broad agreement with our new observational result that Mnc ∝ σ1.57±0.24. This exponent is however in contrast to the value of ∼4 which has been reported previously and interpreted in terms of a regulating feedback mechanism from stellar winds. Finally, it is predicted that host galaxies fainter than MB ∼−20.5 mag (i.e. those 5 not formed in dry merger events) which follow the relation Mbh ∝ σ , and are thus not ‘pseudobulges’, should not have a constant Mbh/Mhost ratio but instead have ∝ 5/2 Mbh Lhost.
    [Show full text]
  • SUPERMASSIVE BLACK HOLES and THEIR HOST SPHEROIDS III. the MBH − Nsph CORRELATION
    The Astrophysical Journal, 821:88 (8pp), 2016 April 20 doi:10.3847/0004-637X/821/2/88 © 2016. The American Astronomical Society. All rights reserved. SUPERMASSIVE BLACK HOLES AND THEIR HOST SPHEROIDS. III. THE MBH–nsph CORRELATION Giulia A. D. Savorgnan Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia; [email protected] Received 2015 December 6; accepted 2016 March 6; published 2016 April 13 ABSTRACT The Sérsic R1 n model is the best approximation known to date for describing the light distribution of stellar spheroidal and disk components, with the Sérsic index n providing a direct measure of the central radial concentration of stars. The Sérsic index of a galaxy’s spheroidal component, nsph, has been shown to tightly correlate with the mass of the central supermassive black hole, MBH.TheMnBH– sph correlation is also expected from other two well known scaling relations involving the spheroid luminosity, Lsph:theLsph–n sph and the MLBH– sph. Obtaining an accurate estimate of the spheroid Sérsic index requires a careful modeling of a galaxy’s light distribution and some studies have failed to recover a statistically significant MnBH– sph correlation. With the aim of re-investigating the MnBH– sph and other black hole mass scaling relations, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, that had been imaged at 3.6 μm with Spitzer.Inthispaper,the third of this series, we present an analysis of the Lsph–n sph and MnBH– sph diagrams.
    [Show full text]
  • Scaling Mass Profiles Around Elliptical Galaxies Observed with Chandra
    Scaling Mass Profiles around Elliptical Galaxies Observed with Chandra and XMM-Newton Y. Fukazawa1, J. G. Betoya-Nonesa1, J. Pu1, A. Ohto1, and N. Kawano1 Department of Physical Science, School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 [email protected] ABSTRACT We investigated the dynamical structure of 53 elliptical galaxies, based on the Chandra archival X-ray data. In X-ray luminous galaxies, a temperature increases with radius and a gas density is systematically higher at the optical outskirts, indicating a presence of a significant amount of the group-scale hot gas. In contrast, X-ray dim galaxies show a flat or declining temperature profile against radius and the gas density is relatively lower at the optical outskirts. Thus it is found that X-ray bright and faint elliptical galaxies are clearly distinguished by the temperature and gas density profile. The mass profile is well scaled by a virial radius r200 rather than an optical-half radius re, and is quite similar at (0.001 − 0.03)r200 between X-ray luminous and dim galaxies, and smoothly connects to those of clusters of galaxies. At the inner region of (0.001 − 0.01)r200 or (0.1 − 1)re, the mass profile well traces a stellar mass with a constant mass-to- light ratio of M/LB =3 − 10(M⊙/L⊙). M/LB ratio of X-ray bright galaxies rises up steeply beyond 0.01r200, and thus requires a presence of massive dark matter halo. From the deprojection analysis combined with the XMM-Newton data, we arXiv:astro-ph/0509521v1 18 Sep 2005 found that X-ray dim galaxies, NGC 3923, NGC 720, and IC 1459, also have a high M/LB ratio of 20–30 at 20 kpc, comparable to that of X-ray luminous galaxies.
    [Show full text]
  • April 14 2018 7:00Pm at the April 2018 Herrett Center for Arts & Science College of Southern Idaho
    Snake River Skies The Newsletter of the Magic Valley Astronomical Society www.mvastro.org Membership Meeting President’s Message Tim Frazier Saturday, April 14th 2018 April 2018 7:00pm at the Herrett Center for Arts & Science College of Southern Idaho. It really is beginning to feel like spring. The weather is more moderate and there will be, hopefully, clearer skies. (I write this with some trepidation as I don’t want to jinx Public Star Party Follows at the it in a manner similar to buying new equipment will ensure at least two weeks of Centennial Observatory cloudy weather.) Along with the season comes some great spring viewing. Leo is high overhead in the early evening with its compliment of galaxies as is Coma Club Officers Berenices and Virgo with that dense cluster of extragalactic objects. Tim Frazier, President One of my first forays into the Coma-Virgo cluster was in the early 1960’s with my [email protected] new 4 ¼ inch f/10 reflector and my first star chart, the epoch 1960 version of Norton’s Star Atlas. I figured from the maps I couldn’t miss seeing something since Robert Mayer, Vice President there were so many so closely packed. That became the real problem as they all [email protected] appeared as fuzzy spots and the maps were not detailed enough to distinguish one galaxy from another. I still have that atlas as it was a precious Christmas gift from Gary Leavitt, Secretary my grandparents but now I use better maps, larger scopes and GOTO to make sure [email protected] it is M84 or M86.
    [Show full text]
  • Im Fokus Hyaden in Den
    DAS UMFASSENDE ASTRONOMISCHE JAHRBUCH Himmels- EXTRA 2 | 2016 EXTRA Almanach 2017 DATEN | DETAILLIERTE KARTEN | PRAXISTIPPS TOP-EREIGNISSE 2017 NGC 4513 UGCA 272 UGC 5336 M 81 Arp 300 ρ UGC 4539 64° Bode's Galaxy 64° Holmberg IX NGC 2959 Σ UGC 5028 RV NGC 4108 R 1400 NGC 2961 5 Σ 1573 NGC 3077 5 NGC 4256 NGC 4221 IC 2574 The Garland σ 2 Σ 1349 σ NGC 4332 Coddington's Nebula FBS 0959+685 NGC 2892 1 NGC 4210 Σ 1306 DERNGC 4441 WEGWEISERNGC 3622 NGC 2976 2 63° 3 UGC 4775 63° DRA NGC 4391 Sh 86 π 1 NGC 4125 VY NGC 4521 HCG 49 NGC 4545 NGC 3682 NGC 4510 NGC 4121 Σ 1350 FÜR DAS GESAMTE JAHR π 2 62° NGC 3231 62° 76 6 NGC 4205 ASTRONOMISCHE EREIGNISSE 57 UGC 5188 NGC 4081 NGC 3392 UGC 4159 UGC 7179 38 WOCHE FÜR WOCHE NGC 3394 35 UGC 6316 61° MCG +11-12-10 61° Σ 1559 NGC 2814 TOTALE S NGC 4605 UGC 5576 32 NGC 3259 β 408 NGC 2820 NGC 2805 τ SONNENFINSTERNIS NGC 3266 56 CGCG 292-85 60° NGC 4041 60° RY 28 5 ο BEOBACHTUNGSTIPPS UGC 6534 UGC 5776 NGC 4036 NGC 3668 23 UGC 7406 29 Muscida IN DEN USA UGC 6520 Σ 1351 MCG +11-14-33 T MCG +10-17-64 NGC 2742A MCG +10-18-51VON EXPERTEN NGC 3359 59° NGC 2880 59° NGC 3725 Σ 1315 UGC 6528 16 NGC 4547 VERSTÄNDLICHE ERKLÄRUNGEN RS NGC 3978 NGC 3762 NGC 2654 75 Shk 105 UGC 4289 NGC 3945 α FÜR EINSTEIGER ΟΣ 235 Dubhe MCG +10-12-103 74 TT 58° NGC 3835A NGC 2742 58° β 1077 UMA UGC 4730 NGC 4358 NGC 3471 NGC 4335 NGC 3835 NGC 3796 ΟΣΣ NGC 4500 Shk 124 92 NGC 2726 UGC 4549 M 40 NGC 3435 NGC 3894NGC 3809 Shk 113 NGC 4290 NGC 3895 20 NGC 2768 NGC 4149 Helix Galaxy 57° 57° 70 Arp 336 Abell 28 UGC 7635 Σ 1544 NGC 2685 UGC
    [Show full text]
  • The Black Hole Mass–Bulge Mass Correlation: Bulges Versus Pseudo-Bulges
    Mon. Not. R. Astron. Soc. 000, 1–22 (2009) Printed 18 July 2021 (MN LATEX style file v2.2) The black hole mass–bulge mass correlation: bulges versus pseudo-bulges Jian Hu? Max-Planck-Institut fur¨ Astrophysik, Karl-Schwarzschild-Straße 1, D-85741 Garching bei Munchen,¨ Germany Accepted 2009 ... Received 2009 ...; in original form 2009 ... ABSTRACT We investigate the scaling relations between the supermassive black holes (SMBHs) mass (Mbh) and the host bulge mass in elliptical galaxies, classical bulges, and pseudo-bulges. We use two-dimensional image analysis software BUDDA to obtain the structural parameters of 57 galaxies with dynamical Mbh measurement, and determine the bulge K-band luminosi- ties (Lbul,K), stellar masses (Ms), and dynamical masses (Md). The updated Mbh-Lbul,K, Mbh- Ms, and Mbh-Md correlations for elliptical galaxies and classical bulges give Mbh'0.006Ms 11 or 0.003Md. The most tight relationship is log(Mbh/M ) = α + β log(Md=10 M ), with α = 8:46 ± 0:05, β = 0:90 ± 0:06, and intrinsic scatter 0 = 0:27 dex. The pseudo-bulges follow their own relations, they harbor an order of magnitude smaller black holes than those in the same massive classical bulges, i.e. Mbh'0.0003Ms or 0.0002Md. Besides the Mbh-σ∗ (bulge stellar velocity dispersion) relation, these bulge type dependent Mbh-Mbul scaling rela- tions provide information for the growth and coevolution histories of SMBHs and their host bulges. We also find the core elliptical galaxies obey the same Mbh-Md relation with other normal elliptical galaxies, that is expected in the dissipationless merger scenario.
    [Show full text]
  • 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
    [Show full text]
  • May 2016 BRAS Newsletter
    May 2016 Issue th Next Meeting: Monday, May 9 at 7PM at HRPO (2nd Mondays, Highland Road Park Observatory) What's In This Issue? President’s Message Secretary's Summary of April Meeting Outreach Report Past Events Summary with Photos of” Rockin’ At The Swamp, Zippety Zoo Fest, Louisiana Earth Day Recent BRAS Forum Entries 20/20 Vision Campaign Geaux Green Committee Meeting Report Message from the HRPO International Astronomy Day Observing Notes: Hydra, the Water Snake, by John Nagle Newsletter of the Baton Rouge Astronomical Society May 2016 President’s Message We had a busy month with outreaches last month, and we have some major outreaches this month: The Transit of Mercury on Monday May 9th, from 6AM to 2PM at HRPO; International Astronomy Day (the 10th consecutive for us) on Saturday May 14th, 3PM to 11PM at HRPO; and Mars Closest Approach (to Earth) on Monday May 30th, 8PM to 12AM at HRPO. Volunteers are welcome. There was a good turnout at the April BRAS meeting with Dr. Giaime, Observatory Head of LIGO Livingston, as our guest speaker. His talk was very informative about the history of the search for gravity waves, Einstein’s theory on gravity waves, and what gravity waves are. The May BRAS meeting’s guest speaker will be Chris Johnson, of the LSU Astronomy Department, giving a presentation titled “Variability of Optical Counterparts to Selected X-ray Sources in the Galactic Bulge”. This is part of his Ph.D. research and has something to do with variable stars and what we can learn from space and ground based telescopes.
    [Show full text]
  • 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.
    [Show full text]
  • Isolated Ellipticals and Their Globular Cluster Systems III. NGC 2271, NGC
    Astronomy & Astrophysics manuscript no. salinas+15_arxiv c ESO 2018 October 5, 2018 Isolated ellipticals and their globular cluster systems III. NGC 2271, NGC 2865, NGC 3962, NGC 4240 and IC 4889 ⋆ R. Salinas1, 2, A.Alabi3, 4, T. Richtler5, and R. R. Lane5 1 Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland 2 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA 3 Tuorla Observatory, University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland 4 Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia 5 Departamento de Astronomía, Universidad de Concepción, Concepción, Chile Accepted 21 Feb 2015 ABSTRACT As tracers of star formation, galaxy assembly and mass distribution, globular clusters have provided important clues to our under- standing of early-type galaxies. But their study has been mostly constrained to galaxy groups and clusters where early-type galaxies dominate, leaving the properties of the globular cluster systems (GCSs) of isolated ellipticals as a mostly uncharted territory. We present Gemini-South/GMOS g′i′ observations of five isolated elliptical galaxies: NGC 3962, NGC 2865, IC 4889, NGC 2271 and NGC 4240. Photometry of their GCSs reveals clear color bimodality in three of them, remaining inconclusive for the other two. All the studied GCSs are rather poor with a mean specific frequency S N 1.5, independently of the parent galaxy luminosity. Considering also previous work, it is clear that bimodality and especially the presence∼ of a significant, even dominant, population of blue clusters occurs at even the most isolated systems, casting doubts on a possible accreted origin of metal-poor clusters as suggested by some models.
    [Show full text]
  • 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
    [Show full text]