DOCSLIB.ORG

Lecture 12: Galaxy Evolution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lecture 12: Galaxy Evolution Lecture 12: Galaxy Evolution • An empirically driven subject: – The Mass versus Age plot of all surveys • Completing the local census: – New dwarf galaxies in the local group – The dwarf galaxy problem • Comparative evolution: – Luminosity function evolution • Luminosity evolution • Number evolution • Practicalities – K-correction – Dust Galaxies – AS 3011 1 MASS ASSEMBLY V. SMOOTH NO METALS V. LUMPY, METAL RICH Galaxies – AS 3011 2 1 The Mass-Age plot 1. Completing the local census 2. Comparative studies Galaxies – AS 3011 3 Dwarf galaxies • Dwarf galaxies are a crucial part of the galaxy evolution puzzle but we know very little about them. • Main theory (see later) proposes that galaxies built-up from smaller units through repeated merging. • Numerical simulations typically predict several thousand dark matter haloes in the local group. • ~ 55 Local Group galaxies known. • ~ 1 new Local Group dwarf galaxy discovered every 18 months. • Very wide range of properties = a combination of late- starters, relics, debris and stunted systems. • Space-density extremely poorly constrained, I.e., important to appreciate that our current backyard census is woefully incomplete. Galaxies – AS 3011 4 2 2 New Local Group galaxies discovered recently… • Bootes • Mv=-5.7 mag • µo=28.1 mag/sq arcsec • Belokurov et al (2006) • Canes Venatici • MV=-7.9 mag • µo=27.8 mag/sq arcsec • Zuker et al (2006) Galaxies – AS 3011 5 The Luminosity-Surface Brightness Plane Galaxies – AS 3011 6 3 Comparative studies • Many comparisons are possible, e.g., – Profile shapes – Gas, dust, plasma and stellar content – Fundamental plane and Faber-Jackson relation – Tully-Fischer relation – Star-formation rates – Line indices, metallicity and colours – Morphologies and luminosity-size relations – Overall and component luminosity functions • Main issues are sample selection bias and demonstrating that a comparison of the high and low z samples is valid, comprehensive and complete. Galaxies – AS 3011 7 The evolution of the galaxy luminosity function ? • Typically allow luminosity and number-density to evolve according too: β γ Lz = Lo(1+ z) , φz = φo(1+ z) β +γ ⇒ Jz = Jo(1+ z) • By constructing two luminosity functions at two redshifts one can constrain β and γ Luminosity Number € Evolution Evolution logφ logφ Abs. magnitude Abs. magnitude Galaxies – AS 3011 8 4 Results from the VLT VIRMOS Deep Survey (Ilbert et al 2006) • Basically no Redshift or little change seen out to z=1 except possible in the blue spheroids ! • More data needed subject rapidly advancing due to new technologies.Galaxies – AS 3011 9 Evolutionary forms • Pure luminosity evolution (brighter in past) • Pure number evolution (more or less in past) • Hierarchical merging (more but fainter in past) • Downsizing (big things form first then fade) • Upsizing (little things form first then fade) • Early monolithic collapse (everything formed at high-z, no change over low z) Galaxies – AS 3011 10 5 E.g., if galaxies are evolving such that β=0.5 and γ=-0.3 what kind of evolution is this and what is the relative luminosity density at z=1 ? • L(z=1)=1.41L(z=0), I.e., galaxies brighter in past • φ(z=1)=0.81φ(z=1), I.e., fewer galaxies in past • 20% of galaxies have formed below z=1, the galaxies have either faded or the new formers been of lower luminosity (downsizing). • J(z=1)=1.15J(z=0) • The luminosity density of the Universe has decreased since z=1. Galaxies – AS 3011 11 Practicalities • 2 effects which can dramatically change a galaxies magnitude ! – Extinction • Caused by attenuation of flux by intervening medium, e.g., dust – K-correction • Important over cosmological distances where observed wavelength is substantially different to emmitted wavelength m − M = 5logd + 25 + A + K K-correction Extinction € correction Galaxies – AS 3011 12 6 Practicalities: Attenuation • E.g., Dust (either in our galaxy, the target galaxy or some inbetween IGM). • Flux received less than it should be by some factor F (0<F<1). FL F i.e.,L ∝ ABS ⇒ 10−0.4m ∝ 10−0.4M App d 2 d 2 M = m − 5log f − 25 + 2.5logF M = m − 5logd − 25 − A • Av=-2.5log(F)=Attenuation in units of V mag (λ dependent) Galaxies – AS 3011 13 € Practicalities: Attenuation • Extinction, if not corrected for can give low values for H0 (I.e., distance are overestimated, H0=v/d) • Where can extinction occur ? HERE HERE HERE HERE HERE • Big problem, typically dust is more transparent at longer wavelength as dust grains are very small. • Major advantage of the near-IR now opening up. Galaxies – AS 3011 14 7 NO DUST i = 0o i = 60o i = 88o (face-on) (edge-on) WITH DUST (B band) Galaxies – AS 3011 15 NGC891 Galaxies – AS 3011 16 8 Impact of dust on global B LF Luminosity density doubles, I.e., only 50% of photons escape ~0.8mag Galaxies – AS 3011 17 Practicalities: K-corrections • Normally we observe through filters, I.e., over some dλ: Typical Galaxy f(λ) Spectrum at z=0 λ λ1 λ2 2 ∞ dλ Lλ = ∫ f (λ)dλ = ∫ T(λ) f (λ)dλ λ 0 T(λ)=Transfer or filter function 1 • As we look towards galaxies at higher redshift through the same filter (or (T(λ)) we are actually receiving flux from shorter wavelengths at a slower€ rate. If we know the spectral shape we can correct for this using the K-correction. Galaxies – AS 3011 18 9 Practicalities: K-correction Typical Galaxy f(λ) f1 Spectrum at z=0 λ1 λ2 Typical Galaxy f2 f(λ) Spectrum at z=1 f3 λ1 λ2 (1+z)λ1 (1+z)λ2 • We measure f2 but we want f3 to compare to f1 ∞ ∫ T(λ (1+ z)) f (λ (1+ z))dλ 0 K(z) = ∞ (1+ z) ∫ T(λ) f (λ)dλ Galaxies – AS 3011 0 19 € Practicalities: K-correction E/S0 dM Sabc Sd/Irr Redshift Galaxies – AS 3011 20 10 Practicalities: K-correction • Typically K(z) is given as: K(z)=az+bz2 • Where a and b are derived for different types Type a b E/S0 3.13 0.24 Sabc 2.63 -0.107 (V-band values) Sd/Irr 0.62 0.14 • E.g., an elliptical galaxy at z=0.3 has an apparent magnitude of mV=23 mag, assuming Av=0 mag what is its absolute magnitude ? cz M = m − 5log( ) + 5logh − 25 − A − K(z) 50 0.5 V 2 M = −18.3+ 5logh0.5 − (3.13z + 0.24z ) Galaxies – AS 3011 M = −19.3+ 5logh0.5 21 € Galaxies – AS 3011 22 11 .
Load more

Recommended publications
  • Studying the Ultraviolet Spectrum of the First Spectroscopically Confirmed Supernova at Redshift
    The Astrophysical Journal, 854:37 (14pp), 2018 February 10 https://doi.org/10.3847/1538-4357/aaa126 © 2018. The American Astronomical Society. All rights reserved. Studying the Ultraviolet Spectrum of the First Spectroscopically Confirmed Supernova at Redshift Two M. Smith1 , M. Sullivan1 , R. C. Nichol2, L. Galbany3 ,C.B.D’Andrea4, C. Inserra1 , C. Lidman5,6 , A. Rest7,8, M. Schirmer9 , A. V. Filippenko10,11 , W. Zheng10, S. Bradley Cenko12 , C. R. Angus1, P. J. Brown13,14 , T. M. Davis5,15, D. A. Finley16, R. J. Foley17, S. González-Gaitán18,19 , C. P. Gutiérrez1 , R. Kessler20,21 , S. Kuhlmann22, J. Marriner16, A. Möller5,23, P. E. Nugent10,24 , S. Prajs1 , R. Thomas24, R. Wolf4, A. Zenteno25, T. M. C. Abbott25, F. B. Abdalla26,27, S. Allam16, J. Annis16 , K. Bechtol28, A. Benoit-Lévy26,29,30, E. Bertin29,30, D. Brooks26 , D. L. Burke31,32 , A. Carnero Rosell33,34, M. Carrasco Kind35,36, J. Carretero37, F. J. Castander38 , M. Crocce38, C. E. Cunha31, L. N. da Costa33,34, C. Davis31, S. Desai39, H. T. Diehl16, P. Doel26,T.F.Eifler40,41, B. Flaugher16, P. Fosalba38, J. Frieman16,20, J. García-Bellido42 , E. Gaztanaga38, D. W. Gerdes43,44 , D. A. Goldstein10,24 , D. Gruen31,32 , R. A. Gruendl35,36 , J. Gschwend33,34, G. Gutierrez16, K. Honscheid45,46, D. J. James47 , M. W. G. Johnson36, K. Kuehn6 , N. Kuropatkin16,T.S.Li16, M. Lima33,48, M. A. G. Maia33,34, J. L. Marshall13,14 , P. Martini45,49 , F. Menanteau35,36, C. J. Miller43,44, R. Miquel37,50 , R. L. C. Ogando33,34, D.
    [Show full text]
  • Clues to the Origin of Parsec to Kilo-Parsec Jet Misalignments In
    A&A manuscript no. ASTRONOMY (will be inserted by hand later) AND Your thesaurus codes are: 03(11.01.2; 11.10.1; 11.17.2; 02.01.2) ASTROPHYSICS Clues to the origin of parsec to kilo-parsec jet misalignments in EGRET sources Xinwu Cao 1 Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030, China 2 National Astronomical Observatories, Chinese Academy of Sciences, China 3 Beijing Astrophysical Center (BAC), Beijing, China Received ; accepted December 21, 1999 Abstract. The apparent position angle difference ∆PA line of sight, but the radio emission is still Doppler boosted between parsec and kilo-parsec jets in blazars can be re- due to a wider beaming cone (von Montigny et al. 1995). lated to the bending properties of the jets. We present The apparent position angle difference ∆PA between correlations between the misalignment ∆PA and the ra- parsec and kilo-parsec jets can be related to the bending tio of radio to broad-line emission for a sample of γ-ray properties of the jets. Many authors have investigated the blazars. The present study is limited to EGRET sources misalignment angle distributions for the different samples due to uniform data for the radio and optical properties of of radio sources (Pearson & Readhead 1988; Conway & these sources being easily available. The broad-line emis- Murphy 1993; Appl et al. 1996; Tingay et al. 1998). If the sion is known to be a good indicator of the accretion power angle between the relativistic jet and the line of the sight for both steep and flat-spectrum quasars.
    [Show full text]
  • K-Correction Surface Brightness Tully-Fisher Relation Spiral Rotation
    Key concepts:! ! !K-correction! !! !Surface brightness! ! !Tully-Fisher relation! ! !Spiral rotation curves! !! ! How to compare galaxies properly! K-corrections! Normally we observe through filters = over some specific dλ. For a typical galaxy spectrum at z=0:! where T is the filter transfer function.! •" Due to redshift effects, the light emitted between λ1 and λ2 becomes light observed between λ1(1+z) and λ2(1+z). Thus both wavelength and bandpass change!! •" Looking at galaxies at higher z through same filter, we therefore receive emission from shorter wavelengths at a slower rate. ! •" Knowing the spectral shape, we can correct for this via the K- correction.! (origin of the term K-correction has been attributed to both Hubble and Wirtz)! Nearby Galaxy! A! Distant Galaxy! C! B! We measure B, but want to measure C to compare to A. ! E! Sa! Sc! Poggianti 1997! K correction in J, H and K band for three types of galaxies. ! Typically given as ! Type !a !b! E/S0 !3.13 !0.24! Sabc !2.63 !-0.107! Sd/Irr !0.62 !0.14 ! !!(V-band values)! •" K-corrections in the optical band large for elliptical galaxies, since they emit little flux in the UV.! •" Smaller corrections for spirals and irregulars.! •" K-corrections depend on observed filter:! –" smaller as you observe further in the red! –" negative in the near-IR! Surface brightness! To quantify the stellar content, look at the total luminosity (in some filter) of a galaxy. How? They don't have sharp edges.! ! Define surface brightness as µ = flux/angular area (mag/arcsec2).! 2 centrally, in B filter, µB ~ 21 mag/arcsec ! 2 further out, µB ~ 25 mag/arcsec ! Surface brightness is independent of distance.! Why? Consider a square galaxy.! move 2 times farther! Covers 16 pixels! Covers 4 pixels! Total flux is 4 times less, but number of pixels (angular area) less by the same factor.! Isophotes! Contours of constant surface brightness are isophotes.
    [Show full text]
  • Distance Modulus
    Astronomy from 4 Perspectives Bi-national Heraeus Sumer School Series for Teacher Students and Teachers I. Cosmology Prof. Dr. Andreas Just Zentrum für Astronomie Heidelberg University Cosmic Distances 22. Aug. 2013 Cosmic Distances - A. Just 1 Cosmic Distances Distance determinations: a fundamental, omnipresent problem in astronomy Local universe Distance ladder Methods/objects/calibration Hubble constant and galaxy distribution expanding curved space Distance and redshift Luminosity, surface brightness, sizes Cornerstone observations 22. Aug. 2013 Cosmic Distances - A. Just 2 Units Units Length: Time: Velocity: Mass: Gravitational constant: 22. Aug. 2013 Cosmic Distances - A. Just 3 Units the astronomical unit AU physical definition from light running time * Attention: semi-major axis of the orbit therefore rounded value: maximum diameter D (e=0.017, b=minor axis): 22. Aug. 2013 Cosmic Distances - A. Just 4 Basic principle Compare an absolute and an apparent property with known dependence on distance Trigonometric parallax . orbital motion of Earth - angular motion of star at sky Distance modulus . Absolute luminosity - apparent brightness . Classification of objects and calibration • Period-luminosity relation (variable stars) • Tully-Fisher relation (spiral galaxies) Kinematic distances . Binary stars: Radial velocities (+ Kepler laws) . Radial velocities – proper motion (+spherical expansion) . Radial velocities – Galactic rotation (+ rotation curve) Hubble flow . Hubble constant and redshift 22. Aug. 2013
    [Show full text]
  • Solar-Motion Correction in Early Extragalactic Astrophysics
    Solar-motion correction in early extragalactic astrophysics Domingos Soares∗ and Luiz Paulo R. Vazy Departamento de F´ısica,ICEx, UFMG | C.P. 702 30123-970, Belo Horizonte | Brazil October 09, 2014 Abstract Redshift observations of galaxies outside the Local Group are fairly common in extragalactic astrophysics. If redshifts are interpreted as aris- ing from radial velocities, these must be corrected by the contamination of the solar motion. We discuss the details of such correction in the way it was performed by the American astronomer Edwin Hubble in his 1929 seminal paper. The investigations of spiral nebulae undertaken by the Swedish astronomer Knut Lundmark, in 1924, are also considered in this context. 1 Introduction The light of distant galaxies | at least outside the Local Group | presents to the observer, specially to the spectroscopist, a singular feature discovered by the American astronomer Vesto Slipher (1875-1969) in the early decades of the XX century: the position of the spectral lines of the chemical elements are, in the great majority of cases, systematically displaced to wavelengths larger than those measured for the same elements (at rest) in earthly laboratories. Being the shifts in the direction of larger wavelengths, they are called redshifts because, in the visible solar spectrum, red has the larger wavelength. Such a nomenclature is adopted even when the object's spectrum is outside the visible arXiv:1312.0472v2 [physics.hist-ph] 9 Oct 2014 range. Less frequently, there is also the blueshift, whose definition is analogous to the redshift. What is the cause of the redshifts of galaxies? Strictly speaking, this is still a question in dispute.
    [Show full text]
  • Galaxy and Mass Assembly (GAMA): Exploring the WISE Web in G12
    Galaxy and mass assembly (GAMA): exploring the WISE cosmic web in G12 Article (Published Version) Jarrett, T H, Cluver, M E, Magoulas, C, Bilicki, M, Alpaslan, M, Bland-Hawthorn, J, Brough, S, Brown, M J I, Croom, S, Driver, S, Holwerda, B W, Hopkins, A M, Loveday, J, Norberg, P, Peacock, J A et al. (2017) Galaxy and mass assembly (GAMA): exploring the WISE cosmic web in G12. Astrophysical Journal, 836 (2). a182. ISSN 0004-637X This version is available from Sussex Research Online: http://sro.sussex.ac.uk/id/eprint/66791/ This document is made available in accordance with publisher policies and may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher’s version. Please see the URL above for details on accessing the published version. Copyright and reuse: Sussex Research Online is a digital repository of the research output of the University. Copyright and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable, the material made available in SRO has been checked for eligibility before being made available. Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way.
    [Show full text]
  • Arxiv:1603.07299V3 [Astro-Ph.GA] 3 Sep 2016 an Approximation of the Contribution of the K-Correction 2 Process to the Uncertainty of the Corrected Measurement
    Draft version May 25, 2018 Preprint typeset using LATEX style emulateapj v. 5/2/11 K-CORRECTIONS: AN EXAMINATION OF THEIR CONTRIBUTION TO THE UNCERTAINTY OF LUMINOSITY MEASUREMENTS Sean E. Lake1, E. L. Wright1 Draft version May 25, 2018 ABSTRACT In this paper we provide formulae that can be used to determine the uncertainty contributed to a measurement by a K-correction and, thus, valuable information about which flux measurement will provide the most accurate K-corrected luminosity. All of this is done at the level of a Gaussian approximation of the statistics involved, that is, where the galaxies in question can be characterized by a mean spectral energy distribution (SED) and a covariance function (spectral 2-point function). This paper also includes approximations of the SED mean and covariance for galaxies, and the three common subclasses thereof, based on applying the templates from Assef et al. (2010) to the objects in zCOSMOS bright 10k (Lilly et al. 2009) and photometry of the same field from Capak et al. (2007), Sanders et al. (2007), and the AllWISE source catalog. Subject headings: Astrophysics, Data Analysis 1. INTRODUCTION SNR of every individual measurement, the answer to the The K-correction was originally defined in the work of question of which filters to K-correct and combine us- Humason et al. (1956). As initially defined, it was lim- ing an inverse variance weighted average is whichever fil- ited to filter transforms from an observer frame photo- ters produce K-corrected quantities with sufficiently high metric filter to the same filter in the galaxy's rest frame.
    [Show full text]
  • Characterizing the Mid-Infrared Extragalactic Sky with Wise and Sdss
    The Astronomical Journal, 145:55 (16pp), 2013 March doi:10.1088/0004-6256/145/3/55 C 2013. The American Astronomical Society. All rights reserved. Printed in the U.S.A. CHARACTERIZING THE MID-INFRARED EXTRAGALACTIC SKY WITH WISE AND SDSS Lin Yan1,E.Donoso1, Chao-Wei Tsai1, D. Stern2,R.J.Assef2,8, P. Eisenhardt2,A.W.Blain3, R. Cutri1, T. Jarrett1, S. A. Stanford4, E. Wright5, C. Bridge6, and D. A. Riechers6,7 1 Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125, USA; [email protected] 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA 3 Department of Physics & Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK 4 Department of Physics, University of California, Davis, CA 95616, USA 5 Astronomy Department, University of California, Los Angeles, CA 90095-1547, USA 6 Astronomy Department, California Institute of Technology, 1200 East California Blvd, Pasadena, CA91125, USA 7 Astronomy Department, Cornell University, Ithaca, NY 14853, USA Received 2012 September 7; accepted 2012 December 10; published 2013 January 18 ABSTRACT The Wide-field Infrared Survey Explorer (WISE) has completed its all-sky survey in four channels at 3.4–22 μm, detecting hundreds of millions of objects. We merge the WISE mid-infrared data with optical data from the Sloan Digital Sky Survey (SDSS) and provide a phenomenological characterization of WISE extragalactic sources. WISE is most sensitive at 3.4 μm(W1) and least sensitive at 22 μm(W4). The W1 band probes massive early-type galaxies out to z 1.
    [Show full text]
  • Arxiv:1402.1456V1 [Astro-Ph.CO] 6 Feb 2014 2.4.1 Intrinsic Variation in Seds
    Dusty Star-Forming Galaxies at High Redshift Caitlin M. Casey1;2, Desika Narayanan3, Asantha Cooray1 1Department of Physics and Astronomy, University of California, Irvine, CA 92697 2Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Dr, Honolulu, HI 96822 3Department of Physics and Astronomy, Haverford College, 370 Lancaster Avenue, Haverford, PA 19041 Abstract Far-infrared and submillimeter wavelength surveys have now established the important role of dusty, star-forming galaxies (DSFGs) in the assembly of stellar mass and the evolution of massive galaxies in the Universe. The brightest 13 of these galaxies have infrared luminosities in excess of 10 L with implied star-formation rates of thousands of solar masses per year. They represent the most intense starbursts in the Universe, yet many are completely optically obscured. Their easy detection at submm wavelengths is due to dust heated by ultraviolet radiation of newly forming stars. When summed up, all of the dusty, star-forming galaxies in the Universe produce an infrared radiation field that has an equal energy density as the direct starlight emission from all galaxies visible at ultraviolet and optical wave- lengths. The bulk of this infrared extragalactic background light emanates from galaxies as diverse as gas-rich disks to mergers of intense starbursting galaxies. Major advances in far-infrared instrumentation in recent years, both space- based and ground-based, has led to the detection of nearly a million DSFGs, yet our understanding of the underlying astrophysics that govern the start and end of the dusty starburst phase is still in nascent stage. This review is aimed at summarizing the current status of DSFG studies, focusing especially on the detailed characterization of the best- understood subset (submillimeter galaxies, who were summarized in the last review of this field over a decade ago, Blain et al.
    [Show full text]
  • The Oxford Handbook of the History of Modern Cosmology Edited by Helge Kragh and Malcolm S
    Frontispiece Frontispiece Edited by Helge Kragh and Malcolm S. Longair The Oxford Handbook of the History of Modern Cosmology Edited by Helge Kragh and Malcolm S. Longair Print Publication Date: Mar 2019 Subject: Physical Sciences Online Publication Date: Apr 2019 (p. ii) Frontispiece Frontispiece: The whole-sky map of the cosmic microwave background radiation (CMB) as observed by the Planck satellite of the European Space Agency (ESA). The image shows largescale structures in the Universe only 380,000 years after the Big Bang. It en­ codes a huge amount of information about the cosmological parameters which describe our Universe. (Courtesy of ESA and the Planck Collaboration) Page 1 of 1 Copyright Page Copyright Page Edited by Helge Kragh and Malcolm S. Longair The Oxford Handbook of the History of Modern Cosmology Edited by Helge Kragh and Malcolm S. Longair Print Publication Date: Mar 2019 Subject: Physical Sciences Online Publication Date: Apr 2019 (p. iv) Copyright Page Great Clarendon Street, Oxford, OX2 6DP, United Kingdom Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries © Oxford University Press 2019 The moral rights of the authors have been asserted First Edition published in 2019 Impression: 1 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by licence or under terms agreed with the appropriate reprographics rights organization.
    [Show full text]
  • K and Evolutionary Corrections from UV to IR B.M
    ASTRONOMY & ASTROPHYSICS MAY I 1997, PAGE 399 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 122, 399-407 (1997) K and evolutionary corrections from UV to IR B.M. Poggianti 1 Kapteyn Instituut?, P.O. Box 800, 9700 AV Groningen, The Netherlands e-mail: [email protected] 2 Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK 3 Royal Greenwich Observatory, Madingley Road, Cambridge CB3 0EZ, UK Received August 11, 1995; accepted July 29, 1996 Abstract. 1 K and evolutionary corrections are given for by using spectrophotometric models. Considering the fact the E, Sa and Sc Hubble types for the U, B, V, R, I, J, that present observations reach high redshifts and pro- H, K filters of the Johnson – Bessell & Brett photometric gressively fainter magnitudes, establishing the connection system and the gri filters of the modified Thuan & Gunn between distant and local galaxies requires more and more system up to the redshift z = 3. Their dependence on the often the knowledge of the galactic evolution and the use time scale of star formation in ellipticals is investigated. of both the corrections. The corrections are computed according to an evolu- tionary synthesis model that reproduces the integrated A number of authors have previously published tables galaxy spectrum in the range 1000 − 25 000 A;˚ such a of K corrections (Hubble 1936; Humason et al. 1956; Oke model makes use of an infrared observed stellar library & Sandage 1968; Schild & Oke 1971; Whitford 1971; Oke and its results are compared with nearby galaxies. 1971; Wells 1972; Pence 1976; Ellis et al. 1977; Code & Evolving spectral energy distributions of the various Welch 1979; Coleman et al.
    [Show full text]
  • The Chemical Evolution of Narrow Emission Line Galaxies: the Key to Their Formation Processes Acta Universitaria, Vol
    Acta Universitaria ISSN: 0188-6266 [email protected] Universidad de Guanajuato México Torres-Papaqui, J. P.; Coziol, R.; Ortega-Minakata, R. A. The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes Acta Universitaria, vol. 21, núm. 4, septiembre, 2011, pp. 82-91 Universidad de Guanajuato Guanajuato, México Available in: http://www.redalyc.org/articulo.oa?id=41620852011 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Universidad de Guanajuato The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes J. P. Torres-Papaqui*, R. Coziol*, R. A. Ortega-Minakata* ABSTRACT Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the masses of the bulge and the mean stellar age of the stellar populations of the host galaxies. It suggests that the spectral variations observed in standard spectroscopic diagnostic diagrams are not due solely to variations of ionization parameters or structures but reect also the chemical evolution of the galaxies, which in turn can be explained by different galaxy formation processes. RESUMEN Utilizando la mayor muestra de galaxias con líneas de emisión angostas disponible hasta el momento, se muestra que sus características espectrales están correlacionadas con diferentes parámetros físicos, como las abundancias químicas, las morfologías, las masas del bulbo, y la edad estelar promedio de las poblaciones estelares de la galaxia antrio- na.
    [Show full text]