DOCSLIB.ORG

1956Aj. X V" O'! the Astronomical Journal

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
1956Aj. X V X O'!V" THE ASTRONOMICAL 1956AJ. JOURNAL Founded by B. A. Gould PUBLISHED BY THE AMERICAN ASTRONOMICAL SOCIETY VOLUME 61 1956 April - No. 1237 NUMBER 3 REDSHIFTS AND MAGNITUDES OF EXTRAGALACTIC NEBULAE * By M. L. HUMASON, N. U. MAYALL, and A. R. SANDAGE Abstract. There are three main sections to the present discussion. Part I contains redshifts of 620 extragalactic nebulae observed at Mount Wilson and Palomar. Included in these data are redshifts for 26 clusters of nebulae. Part II contains redshifts for 300 nebulae observed at Lick, together with a comparison of results for 114 nebulae in common with the Mount Wilson-Palomar lists. Part III is a discussion of these new redshift data in combination with photometric data. The redshift-apparent magnitude relation is investigated for (1) field nebulae with and without regard to nebular type, (2) isolated groups, and (3) clusters of nebulae. The principal corrections applied to the apparent magnitudes are dis- cussed in two of the three appendices. Appendix A gives the procedure for correcting the published magnitudes for the effect of different photometer apertures. Appendix B describes the theory and computation of the correction for the selective effect of redshifts. In the final Appendix C, a provisional evaluation of the Hubble redshift parameter H is made by two independent methods. The principal results of this study may be stated as follows. (1) For those nebulae observed in common there is a negligible mean systematic difference between the redshifts from the two sources. (2) Spectrographico coverage is 63 per cent complete to mpg = 12.9 in the Shapley-Ames catalogue for nebulae north of ô = —30 . (3) The log redshift-magni- tude relation for field nebulae with and without regard to type is linear to within the accuracy of the data. (4) The log redshift-magnitude relation for the cluster data confirms the linearity for small AX/Xo and shows an apparently significant departure from linearity for shifts of the order of AX/Xo = 0.2. This non-linearity indicates deceleration of the expansion if interpretation is made by theoretical equations due to Robertson. Because of the cosmological significance of this last result, the accuracies of the various quantities that lead to it are examined. It is concluded that a deceleration should be regarded as tentative until Whitford’s results are available for the spectral energy distribution of the distant nebulae, and until an adequate theory of stellar evolution is advanced to explain the Stebbins-Whitford effect. (5) The Hubble redshift parameter H is provisionally estimated from (a) the magnitudes of resolved stars in NGC 4321 that have been isolated from the emission H11 regions, and (b) from the assumption that the brightest field and cluster nebulae are giants of luminosity comparable to the Andromeda nebula, with the result that Ü = 180 km/sec per 106 pc. GENERAL INTRODUCTION nebulae, he regarded them in sum as a ‘‘prelimi- nary reconnaissance.” This appraisal, although More than 25 years ago Hubble (1929) an- a characteristic understatement, emphasized the nounced a relationship between velocities and need for many more nebular redshifts and mag- distances of extragalactic nebulae. Since he real- nitudes. These spectrographic and photometric ized that this first formulation referred to only a data are now available in considerable numbers, relatively small distance, he initiated an explora- on a systematic basis, and with improved preci- tory program to follow the relationship to the greatest distances attainable with the largest tele- sion, chiefly as the result of Hubble’s inspiring scope. The successful outcome of that program influence on his colleagues. has become widely known, especially through This paper contains as its principal new mate- publication of his book, The Realm of the Nebulae rial redshifts for over 800 nebulae observed dur- (Hubble 1936a), and his professional lectures. ing the 20-year interval from 1935 to 1955. While The last of these (Hubble 1953) summarizes the these redshifts doubtless could be discussed observational basis for the early restricted veloc- alone, one of the main reasons for obtaining them ity-distance relation, and the later far-reaching was their use as the higher-precision, independent law of redshifts. variable in correlations with nebular magnitudes. Despite the comprehensiveness of Hubble’s This unified treatment of spectrographic and extragalactic researches that used the 100-inch * Mount Wilson and Palomar Observatories, Reprint to the limits of its power for observations of faint No. 181. Lick Observatory Bulletin, No. 542. © American Astronomical Society • Provided by the NASA Astrophysics Data System X O'!V" 98 THE ASTRONOMICAL JOURNAL 61, No. 1237 photometric data follows previous practice by the same telescope, spectrograph and two-prism Hubble, who, had he lived, would have partici- dispersion (except for one nebula observed with 1956AJ. pated as the senior author in the analysis and three prisms), it was feasible to list for each plate discussion. such details as slit-width, emulsion, exposure, Since photography of nebular spectra 20 years and an index of accuracy based on the agreement ago required much more telescope time than now, between redshifts for different spectral features. a cooperative program of nebular spectroscopy Such information reveals something of the tech- was started in 1935 at the Mount Wilson and nique, observing time, and order of precision in- Lick Observatories. The field was divided accord- volved in low-dispersion spectroscopy of nebulae. ing to the instrumental facilities. At Mount Following the last list of spectrographic data, Wilson, the fainter catalogued nebulae and the Table V and notes, the redshifts are discussed for faintest and smallest cluster nebulae were nat- (1) systematic differences for nebulae observed ural selections for the superior light-gathering in common at Mount Wilson-Palomar and at power and scale of the 100-inch ; at Lick, the Lick, and (2) degree of completeness in terms of brighter catalogued nebulae and the larger spirals the Shapley-Ames catalogue magnitudes. of low surface brightness were appropriate ob- Part III. Discussion of the Spectrographic and jects for the moderate capabilities of the 36-inch Photometric Data. This section contains quanti- Crossley. At both observatories the Shapley- tative evaluations of the relationships between Ames Catalogue of Bright External Galaxies (1932) redshifts and magnitudes for (1) field nebulae was used as the principal finding list and source with and without regard to nebular type, (2) iso- of magnitudes. Originally, the two programs sep- lated groups, and (3) the cluster nebulae. The arated the nebulae north of ô = — 30 o at the magnitudes for field nebulae were obtained prin- catalogue magnitude of 11.6, except that the cipally from Pettit’s (1954) large catalogue, sup- Crossley was used for most objects north of plemented with measures by Stebbins and Whit- the 100-inch limit at 5 = +64°. As the work ford (1952). The magnitudes for the faintest progressed, considerable overlap resulted over a cluster nebulae were obtained photographically fairly wide range in magnitude because of interest with the 200-inch and a jiggle-camera. Before in individual objects for special purposes, and the magnitudes were used, all were corrected for more than 100 nebulae were observed in common. the effects of different photometer apertures by The remainder of this paper is divided into the procedure given in Appendix A. The appen- three parts, which were written by the authors dix gives, moreover, the list of corrected magni- in the order shown by the line following the title. tudes for field nebulae, together with an analysis These parts may be described as follows : of the overlap between the Pettit and the Stebbins and Whitford photoelectric data, on the one hand, Part I. The Mount Wilson-Palomar Lists of and between the Pettit data and Holmberg’s un- Redshifts. These are subdivided into three tables published precision photographic material, on the that include non-cluster objects, bright nebulae other. Additional corrections to all magnitudes in clusters, and faint nebulae in clusters. This were made for the effects of redshift. These so- arrangement reflects the basic programs and called K corrections were computed by the pro- facilitates the treatment of the material for the cedure given in Appendix B. The redshift-magni- numerous brighter nebulae in the nearer clusters, tude correlations are discussed with theoretical such as those in Virgo and Coma, and the fewer relations given by Robertson (1955), in simplified fainter nebulae in the more distant clusters. Be- form for the nearer field nebulae, and with a cause of the considerable mass of the material, second-order term for the cluster nebulae. Finally, which was obtained with several different tele- in Appendix C a provisional evaluation of the scopes and with a variety of spectrographs and Hubble redshift parameter iJ is made from dis- dispersions, it was impracticable to include in the tance indicators calibrated in the nearby resolved tables all the detailed data for individual plates. systems. Instead, the number of plates and the dispersions are indicated in a summary column, and a mean PART I. MOUNT WILSON-PALOMAR redshift is given for each nebula. LISTS OF REDSHIFTS Part II. The Lick List of Redshifts. These are given in a single table, because the observing The systematic spectroscopic observation of program placed no special emphasis on cluster extragalactic nebulae at the Mount Wilson Ob- nebulae. Since all the plates were obtained with servatory was begun in 1928 at the request of © American Astronomical Society • Provided by the NASA Astrophysics Data System X O'!V" 1956 April THE ASTRONOMICAL JOURNAL 99 Edwin Hubble, in order to test further the relation were made at the Cassegrain focus with a spec- he had found (Hubble 1929) between redshifts trograph which could not be rotated, using the 1956AJ.
Load more

Recommended publications
  • A Mean-Line Model to Predict the Design Performance of Radial Inflow Turbines in Organic Rankine Cycles
    UNIVERSITÀ DEGLI STUDI DI PADOVA DIPARTIMENTO DI INGEGNERIA INDUSTRIALE CORSO DI LAUREA MAGISTRALE IN INGEGNERIA ENERGETICA TECHNISCHE UNIVERSITÄT BERLIN INSTITUT FÜR ENERGIETECHNIK Tesi di Laurea Magistrale in Ingegneria Energetica A MEAN-LINE MODEL TO PREDICT THE DESIGN PERFORMANCE OF RADIAL INFLOW TURBINES IN ORGANIC RANKINE CYCLES Relatori: Prof. Andrea Lazzaretto Prof.ssa Tatjana Morozyuk (Technische Universität Berlin) Correlatore: Ing. Giovanni Manente Laureando: ANDREA PALTRINIERI ANNO ACCADEMICO 2013/2014 ii Abstract This Master Thesis contributes to the knowledge and the optimization of radial inflow turbine for the Organic Rankine Cycles application. A large amount of literature sources is analysed to understand in the better way the context in which this work is located. First of all, the ORC technology is studied, taking care of all the scientific aspects that characterize it: applications, cycle configurations and selection of the optimal working fluids. After that, the focus is pointed on the expanders, as they are the most important components of this kind of power production plants. Nevertheless. Their behaviour is not always wisely considered in an organic vision of the cycle. In fact, it has been noticed that mostly literature concerning the optimization of ORC considers the performances of the expander as a constant, omitting in this way an essential part of the optimisation process. Starting from these observations, in this Master Thesis radial inflow turbines are carefully analysed, performing a theoretical investigation of the achievable performance. Starting from a critical study of publications concerning the design of radial expanders, a theoretical model is proposed. Then, a design procedure of the geometrical and thermo dynamical characteristics of radial inflow turbine operating whit fluid R-245fa is implemented in a Matlab code.
    [Show full text]
  • Infrared Spectroscopy of Nearby Radio Active Elliptical Galaxies
    The Astrophysical Journal Supplement Series, 203:14 (11pp), 2012 November doi:10.1088/0067-0049/203/1/14 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. INFRARED SPECTROSCOPY OF NEARBY RADIO ACTIVE ELLIPTICAL GALAXIES Jeremy Mould1,2,9, Tristan Reynolds3, Tony Readhead4, David Floyd5, Buell Jannuzi6, Garret Cotter7, Laura Ferrarese8, Keith Matthews4, David Atlee6, and Michael Brown5 1 Centre for Astrophysics and Supercomputing Swinburne University, Hawthorn, Vic 3122, Australia; [email protected] 2 ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) 3 School of Physics, University of Melbourne, Melbourne, Vic 3100, Australia 4 Palomar Observatory, California Institute of Technology 249-17, Pasadena, CA 91125 5 School of Physics, Monash University, Clayton, Vic 3800, Australia 6 Steward Observatory, University of Arizona (formerly at NOAO), Tucson, AZ 85719 7 Department of Physics, University of Oxford, Denys, Oxford, Keble Road, OX13RH, UK 8 Herzberg Institute of Astrophysics Herzberg, Saanich Road, Victoria V8X4M6, Canada Received 2012 June 6; accepted 2012 September 26; published 2012 November 1 ABSTRACT In preparation for a study of their circumnuclear gas we have surveyed 60% of a complete sample of elliptical galaxies within 75 Mpc that are radio sources. Some 20% of our nuclear spectra have infrared emission lines, mostly Paschen lines, Brackett γ , and [Fe ii]. We consider the influence of radio power and black hole mass in relation to the spectra. Access to the spectra is provided here as a community resource. Key words: galaxies: elliptical and lenticular, cD – galaxies: nuclei – infrared: general – radio continuum: galaxies ∼ 1. INTRODUCTION 30% of the most massive galaxies are radio continuum sources (e.g., Fabbiano et al.
    [Show full text]
  • Multimedia Foundations Glossary of Terms Chapter 8 – Text
    Multimedia Foundations Glossary of Terms Chapter 8 – Text Ascender Any part of a lowercase character that extends above the x-height, such as in the vertical stem of the letter b or h. Baseline And imaginary plane where the bottom edge of each character’s main body rests. Baseline Shift Refers to shifting the base of certain characters (up or down) to a new position. Capline An imaginary line denoting the tops of uppercase letters. Counter The enclosed or partially enclosed open area in letters such as O and G. Descender Any part of a character that extends below the baseline; such as in the bottom stroke of a y or p. Flush Left The alignment of text along a common left-edged line. Font Family A collection of related fonts – all of the bolds, italics, and so forth, in their various sizes. Gridline A matrix of evenly spaced vertical and horizontal lines that are superimposed overtop of the design window as a visual aid for aligning objects. Justification The term used when both the left and right edges of a paragraph are vertically aligned. Kerning A technique that selectively varies the amount of space between a single pair of letters and accounts for letter shape; allowing letters like A and V to extend into one another’s virtual blocks. Leading A term used to define the amount of space between vertically adjacent lines of text. Legibility Refers to a typeface’s characteristics and can change depending on font size. The more legible a typeface, the easier it is at a glance to distinguish and identify letters, numbers, and symbols.
    [Show full text]
  • Web Typography │ 2 Table of Content
    Imprint Published in January 2011 Smashing Media GmbH, Freiburg, Germany Cover Design: Ricardo Gimenes Editing: Manuela Müller Proofreading: Brian Goessling Concept: Sven Lennartz, Vitaly Friedman Founded in September 2006, Smashing Magazine delivers useful and innovative information to Web designers and developers. Smashing Magazine is a well-respected international online publication for professional Web designers and developers. Our main goal is to support the Web design community with useful and valuable articles and resources, written and created by experienced designers and developers. ISBN: 978-3-943075-07-6 Version: March 29, 2011 Smashing eBook #6│Getting the Hang of Web Typography │ 2 Table of Content Preface The Ails Of Typographic Anti-Aliasing 10 Principles For Readable Web Typography 5 Principles and Ideas of Setting Type on the Web Lessons From Swiss Style Graphic Design 8 Simple Ways to Improve Typography in Your Designs Typographic Design Patterns and Best Practices The Typography Dress Code: Principles of Choosing and Using Typefaces Best Practices of Combining Typefaces Guide to CSS Font Stacks: Techniques and Resources New Typographic Possibilities with CSS 3 Good Old @Font-Face Rule Revisted The Current Web Font Formats Review of Popular Web Font Embedding Services How to Embed Web Fonts from your Server Web Typography – Work-arounds, Tips and Tricks 10 Useful Typography Tools Glossary The Authors Smashing eBook #6│Getting the Hang of Web Typography │ 3 Preface Script is one of the oldest cultural assets. The first attempts at written expressions date back more than 5,000 years ago. From the Sumerians cuneiform writing to the invention of the Gutenberg printing press in Medieval Germany up to today՚s modern desktop publishing it՚s been a long way that has left its impact on the current use and practice of typography.
    [Show full text]
  • Rotation Curves of High-Resolution LSB and SPARC Galaxies with Fuzzy and Multistate (Ultralight Boson) Scalar field Dark Matter
    MNRAS 475, 1447–1468 (2018) doi:10.1093/mnras/stx3208 Advance Access publication 2017 December 12 Rotation curves of high-resolution LSB and SPARC galaxies with fuzzy and multistate (ultralight boson) scalar field dark matter T. Bernal,1‹† L. M. Fernandez-Hern´ andez,´ 1 T. Matos2‡ andM.A.Rodr´ıguez-Meza1‡ 1Departamento de F´ısica, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, Ciudad de Mexico´ 11801, Mexico 2Departamento de F´ısica, Centro de Investigacion´ y de Estudios Avanzados del IPN, AP 14-740, Ciudad de Mexico´ 07000, Mexico Accepted 2017 December 8. Received 2017 December 8; in original form 2017 January 4 ABSTRACT Cold dark matter (CDM) has shown to be an excellent candidate for the dark matter (DM) of the Universe at large scales; however, it presents some challenges at the galactic level. The scalar field dark matter (SFDM), also called fuzzy, wave, Bose–Einstein condensate, or ultralight axion DM, is identical to CDM at cosmological scales but different at the galactic ones. SFDM forms core haloes, it has a natural cut-off in its matter power spectrum, and it predicts well-formed galaxies at high redshifts. In this work we reproduce the rotation curves of high- resolution low surface brightness (LSB) and SPARC galaxies with two SFDM profiles: (1) the soliton+NFW profile in the fuzzy DM (FDM) model, arising empirically from cosmological simulations of real, non-interacting scalar field (SF) at zero temperature, and (2) the multistate SFDM (mSFDM) profile, an exact solution to the Einstein–Klein–Gordon equations for a real, self-interacting SF, with finite temperature into the SF potential, introducing several quantum states as a realistic model for an SFDM halo.
    [Show full text]
  • Why Gravity Cannot Be Quantized Canonically, and What We Can We Do About It
    WHY GRAVITY CANNOT BE QUANTIZED CANONICALLY, AND WHAT WE CAN WE DO ABOUT IT Philip D. Mannheim Department of Physics University of Connecticut Presentation at Miami 2013, Fort Lauderdale December 2013 1 GHOST PROBLEMS, UNITARITY OF FOURTH-ORDER THEORIES AND PT QUANTUM MECHANICS 1. P. D. Mannheim and A. Davidson, Fourth order theories without ghosts, January 2000 (arXiv:0001115 [hep-th]). 2. P. D. Mannheim and A. Davidson, Dirac quantization of the Pais-Uhlenbeck fourth order oscillator, Phys. Rev. A 71, 042110 (2005). (0408104 [hep-th]). 3. P. D. Mannheim, Solution to the ghost problem in fourth order derivative theories, Found. Phys. 37, 532 (2007). (arXiv:0608154 [hep-th]). 4. C. M. Bender and P. D. Mannheim, No-ghost theorem for the fourth-order derivative Pais-Uhlenbeck oscillator model, Phys. Rev. Lett. 100, 110402 (2008). (arXiv:0706.0207 [hep-th]). 5. C. M. Bender and P. D. Mannheim, Giving up the ghost, Jour. Phys. A 41, 304018 (2008). (arXiv:0807.2607 [hep-th]) 6. C. M. Bender and P. D. Mannheim, Exactly solvable PT-symmetric Hamiltonian having no Hermitian counterpart, Phys. Rev. D 78, 025022 (2008). (arXiv:0804.4190 [hep-th]) 7. C. M. Bender and P. D. Mannheim, PT symmetry and necessary and sufficient conditions for the reality of energy eigenvalues, Phys. Lett. A 374, 1616 (2010). (arXiv:0902.1365 [hep-th]) 8. P. D. Mannheim, PT symmetry as a necessary and sufficient condition for unitary time evolution, Phil. Trans. Roy. Soc. A. 371, 20120060 (2013). (arXiv:0912.2635 [hep-th]) 9. C. M. Bender and P. D. Mannheim, PT symmetry in relativistic quantum mechanics, Phys.
    [Show full text]
  • Exoplanet.Eu Catalog Page 1 # Name Mass Star Name
    exoplanet.eu_catalog # name mass star_name star_distance star_mass OGLE-2016-BLG-1469L b 13.6 OGLE-2016-BLG-1469L 4500.0 0.048 11 Com b 19.4 11 Com 110.6 2.7 11 Oph b 21 11 Oph 145.0 0.0162 11 UMi b 10.5 11 UMi 119.5 1.8 14 And b 5.33 14 And 76.4 2.2 14 Her b 4.64 14 Her 18.1 0.9 16 Cyg B b 1.68 16 Cyg B 21.4 1.01 18 Del b 10.3 18 Del 73.1 2.3 1RXS 1609 b 14 1RXS1609 145.0 0.73 1SWASP J1407 b 20 1SWASP J1407 133.0 0.9 24 Sex b 1.99 24 Sex 74.8 1.54 24 Sex c 0.86 24 Sex 74.8 1.54 2M 0103-55 (AB) b 13 2M 0103-55 (AB) 47.2 0.4 2M 0122-24 b 20 2M 0122-24 36.0 0.4 2M 0219-39 b 13.9 2M 0219-39 39.4 0.11 2M 0441+23 b 7.5 2M 0441+23 140.0 0.02 2M 0746+20 b 30 2M 0746+20 12.2 0.12 2M 1207-39 24 2M 1207-39 52.4 0.025 2M 1207-39 b 4 2M 1207-39 52.4 0.025 2M 1938+46 b 1.9 2M 1938+46 0.6 2M 2140+16 b 20 2M 2140+16 25.0 0.08 2M 2206-20 b 30 2M 2206-20 26.7 0.13 2M 2236+4751 b 12.5 2M 2236+4751 63.0 0.6 2M J2126-81 b 13.3 TYC 9486-927-1 24.8 0.4 2MASS J11193254 AB 3.7 2MASS J11193254 AB 2MASS J1450-7841 A 40 2MASS J1450-7841 A 75.0 0.04 2MASS J1450-7841 B 40 2MASS J1450-7841 B 75.0 0.04 2MASS J2250+2325 b 30 2MASS J2250+2325 41.5 30 Ari B b 9.88 30 Ari B 39.4 1.22 38 Vir b 4.51 38 Vir 1.18 4 Uma b 7.1 4 Uma 78.5 1.234 42 Dra b 3.88 42 Dra 97.3 0.98 47 Uma b 2.53 47 Uma 14.0 1.03 47 Uma c 0.54 47 Uma 14.0 1.03 47 Uma d 1.64 47 Uma 14.0 1.03 51 Eri b 9.1 51 Eri 29.4 1.75 51 Peg b 0.47 51 Peg 14.7 1.11 55 Cnc b 0.84 55 Cnc 12.3 0.905 55 Cnc c 0.1784 55 Cnc 12.3 0.905 55 Cnc d 3.86 55 Cnc 12.3 0.905 55 Cnc e 0.02547 55 Cnc 12.3 0.905 55 Cnc f 0.1479 55
    [Show full text]
  • Betekenis Van De Methode Van Taguchi Voor Off-Line Kwaliteitscontrole Voor De Bedrijfsmechanisatie
    Betekenis van de methode van Taguchi voor off-line kwaliteitscontrole voor de bedrijfsmechanisatie Citation for published version (APA): Coenen, F. J. (1991). Betekenis van de methode van Taguchi voor off-line kwaliteitscontrole voor de bedrijfsmechanisatie. (TH Eindhoven. Afd. Werktuigbouwkunde, Vakgroep Produktietechnologie : WPB; Vol. WPA1017). Technische Universiteit Eindhoven. Document status and date: Gepubliceerd: 01/01/1991 Document Version: Uitgevers PDF, ook bekend als Version of Record Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.
    [Show full text]
  • Atmob Newsletterjulyfinal
    expensive. I found that out when I went to Criterion Optical Co. in Hartford with a very small budget for a telescope, and the nice person I talked with finally reached into a drawer and pulled out a slightly scratched small mirror and offered it to me cheap, along STAR with a slightly defective focuser (no knob or rack, but it did have a small diagonal attached), and some miscellaneous small lenses and cardboard spacers for making an eyepiece. He also gave me FIELDS some brief verbal instructions on how to put all this together into a Newtonian telescope. Next stop the hardware store to buy a piece of stove pipe, and I was in business after a little construction work. There were no astronomy books in our local Newsletter of the library, but just sweeping the dark sky (back then it was dark) and Amateur Telescope Makers of Boston picking out some interesting sights – even with no idea what they Including the Bond Astronomical Club were or what they were called - was a thrill for a teenager. Established in 1934 In the Interest of Telescope Making & Using It would be nice if I could tell you that I stayed with the hobby continuously from then up to now. But the truth is that other Vol. 22, No. 7 July 2010 things- college, grad school and then the “real world”- soon intervened and demanded attention and my astronomy activities faded into the past. This Month’s Meeting… th Then for my birthday about ten years ago- out of the blue and Thursday, July 8 , 2010 at 8:00 PM with no warning- my wife and two boys decided to give me a Phillips Auditorium telescope.
    [Show full text]
  • A Search For" Dwarf" Seyfert Nuclei. VII. a Catalog of Central Stellar
    TO APPEAR IN The Astrophysical Journal Supplement Series. Preprint typeset using LATEX style emulateapj v. 26/01/00 A SEARCH FOR “DWARF” SEYFERT NUCLEI. VII. A CATALOG OF CENTRAL STELLAR VELOCITY DISPERSIONS OF NEARBY GALAXIES LUIS C. HO The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 JENNY E. GREENE1 Department of Astrophysical Sciences, Princeton University, Princeton, NJ ALEXEI V. FILIPPENKO Department of Astronomy, University of California, Berkeley, CA 94720-3411 AND WALLACE L. W. SARGENT Palomar Observatory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 To appear in The Astrophysical Journal Supplement Series. ABSTRACT We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being rela- −1 tively late-type systems with low velocity dispersions (∼<100kms ). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can ac- commodate composite stellar populations by calculating an optimal linear combination of input stellar templates. The original Palomar survey data were taken under conditions that are not ideally suited for deriving stellar veloc- ity dispersions for galaxies with a wide range of Hubble types. We describe an effective strategy to circumvent this complication and demonstrate that we can still obtain reliable velocity dispersions for this sample of well-studied nearby galaxies. Subject headings: galaxies: active — galaxies: kinematics and dynamics — galaxies: nuclei — galaxies: Seyfert — galaxies: starburst — surveys 1. INTRODUCTION tors, apertures, observing strategies, and analysis techniques.
    [Show full text]
  • Mandm Direct Spreads
    Touring the moonlit Spring Skies... Observations from Saturday 11th May 2019 8.30pm - 2.15am Equipment used: TEC 140, tracking Nova Hitch Alt-Az with slow-mo controls and encoders on a Berlebach Planet, iPad Air2 running SkySafari Pro 5, Nexus WiFi, 10 and 21mm Ethos, Baader BBHS diagonal, Lumicon 2” UHC and OIII filters in a True-Tech manual filter wheel. Mixed forecasts, Clear Outside suggesting 27% cloud around midnight, Xasteria saying clear, Clear Outside loaded from within Xasteria offering something in-between (how do you get that, hey!?) and Meteoblue forecasting clear skies from 11 but with poor ‘Index 2’ and Jet Stream readings.... Having neglected visual astronomy for many months (having spent my time finally getting the imaging gear to play ball), I spent forty odd minutes re-learning how to set everything back up - in fact, it be on offer with the moon in attendance... took longer than it does to wheel out the imaging gear. Times have changed, my usual (100% visual) observing buddy was having a go at imaging (spectroscopy), so I was on my own for this evening. It meant I’d have to keep my own notes for a change, but also allow me to go at my own pace as I reacquainted myself with the night sky. By 8.30 I was ready to go, clear skies, still a shade of blue with a half moon hanging over in the south western sky. Temperature rapidly dropping. 21mm eyepiece in place easily held the entire moon. Fantastic details, sharp, contrasty, zero colour..
    [Show full text]
  • Arxiv:Astro-Ph/9906499V1 30 Jun 1999
    to appear in AJ Globular Cluster Systems I: V − I Color Distributions Karl Gebhardt 1,3 University of California Observatories / Lick Observatory, University of California, Santa Cruz, CA 95064 Electronic mail: [email protected] Markus Kissler-Patig 2 European Southern Observatory, Karl–Schwarzschild–Str. 2, 85748 Garching, Germany University of California Observatories / Lick Observatory, University of California, Santa Cruz, CA 95064 Electronic mail: [email protected] ABSTRACT We have compiled data for the globular cluster systems of 50 galaxies from the HST WFPC2 archive, of which 43 are type S0 or earlier. In this paper, we present the data set and derive the V − I color distributions. We derive the first four moments of the color distributions, as well as a measure for their non–unimodality. The number of globular clusters in each galaxy ranges from 18 (in NGC 2778) to 781 (NGC 5846). For those systems having more than 100 clusters, seven of sixteen (44%) show significant bimodality. Overall, roughly half of all the systems in our sample show hints of a bimodal color distribution. In general, the distributions of the faint galaxies are consistent with unimodality, whereas those of the brighter galaxies are not. We also find a number of systems with narrow color distributions—with both mean red and arXiv:astro-ph/9906499v1 30 Jun 1999 blue colors—suggesting that systems exist with only metal–rich or only metal–poor globular clusters. We discuss their possible origins. In comparing the moments of the V − I distributions with various
    [Show full text]