DOCSLIB.ORG

A Supernova Origin for Dust in a High-Redshift Quasar

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Supernova Origin for Dust in a High-Redshift Quasar A SUPERNOVA ORIGIN FOR DUST IN A HIGH-REDSHIFT QUASAR R. Maiolino ∗, R. Schneider †∗, E. Oliva ‡∗, S. Bianchi §, A. Ferrara ¶, F. Mannucci§, M. Pedani‡, M. Roca Sogorb k ∗ INAF - Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy † “Enrico Fermi” Center, Via Panisperna 89/A, 00184 Roma, Italy ‡ Telescopio Nazionale Galileo, C. Alvarez de Abreu, 70, 38700 S.ta Cruz de La Palma, Spain § CNR-IRA, Sezione di Firenze, Largo Enrico Fermi 5, 50125 Firenze, Italy ¶ SISSA/International School for Advanced Studies, Via Beirut 4, 34100 Trieste, Italy k Astrofisico Fco. S`anchez, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain Interstellar dust plays a crucial role in the evolution of the Universe by assisting the formation of molecules1, by triggering the formation of the first low-mass stars2, and by absorbing stellar ultraviolet-optical light and subsequently re-emitting it at infrared/millimetre wavelengths. Dust is thought to be produced predominantly in the envelopes of evolved (age >1 Gyr), low-mass stars3. This picture has, however, recently been brought into question by the discovery of large masses of dust in the host galaxies of quasars4,5 at redshift z > 6, when the age of the Universe was less than 1 Gyr. Theoretical studies6,7,8, corroborated by observations of nearby supernova remnants9,10,11, have suggested that supernovae provide a fast and efficient dust formation environment in the early Universe. Here we report infrared observations of a quasar at redshift 6.2, which are used to obtain directly its dust extinction curve. We then show that such a curve is in excellent agreement with supernova dust models. This result demonstrates a supernova origin for dust in this high-redshift quasar, from which we infer that most of the dust at high redshifts has probably the same origin. arXiv:astro-ph/0409577v1 24 Sep 2004 Powerful quasars offer an optimal tool An important class of quasars are the for detailed studies of dust in their host Broad Absorption Line (BAL) quasars, galaxies out to very high redshifts. Dust whose UV spectrum is characterized by extinction is inferred through redden- blueshifted, deep and broad absorption ing of the quasar UV/optical continuum features associated with highly ionized emission. The extinction curve (Aλ = atomic species, which trace powerful out- 1.086 τλ, where τλ is the wavelength- flows of dense gas along our line of sight. dependent optical depth) of dust associ- Low Ionization BAL (LoBAL) quasars are ated with low redshift, mildly obscured characterized by additional low ionization quasars has been typically found to be absorption lines, probably associated with consistent with that of the Small Magel- higher column densities of gas. LoBAL lanic Cloud (SMC)12,13,14, while for heav- quasars at z < 4 are always significantly ily absorbed quasars there are indica- reddened by dust (associated with the out- tions that the extinction curve may be flowing gas), and therefore they are ideal different15,16. 2 R. Maiolino et al. laboratories to investigate the properties be fitted with a non-BAL (unreddened) of dust. quasar template with a slope α = −2.1 α By means of low resolution near-IR (Fλ ∝ λ ), which is shown with a dot- spectroscopic observations we have re- ted line in Fig.1. Such a blue slope is cently identified a few BAL quasars at consistent with the intrinsic slope of – z ≈ 5 − 6 (Maiolino et al. 2004). The 2.01 inferred by Reichard et al. (2003)13 most distant among them is the LoBAL for BAL quasars. The observed spec- quasar SDSSJ104845.05+463718.3 (here- trum deviates significantly from the non- after SDSS1048+46). At a redshift z = BAL unreddened template only at λrest < 6.193 (based on a new medium resolution 1700 A.˚ While such a deviation was ini- spectrum around MgIIλ2798; Maiolino et tially ascribed to a severe blend of the al. in prep), this is the only LoBAL CIV and SiIV troughs in the low resolu- at z > 5 currently known, and offers a tion spectrum, the new medium resolu- unique chance of investigating the dust tion spectrum (whose unsmoothed and en- extinction curve at z ≈ 6. This quasar larged version is shown in Fig. 1b) clearly was re-observed at higher spectral reso- shows that this is not the case. The con- lution with the goal of de-blending the tinuum outside the troughs is indeed red- deep troughs characterizing its spectrum der than expected by the extrapolation of and of estimating the reddening of the the longer wavelength spectrum through continuum. Observations were obtained the unreddened quasar template (dotted in February 2004 with the Near Infrared line). If such reddening at short wave- Camera Spectrometer (NICS18) at the lengths is due to dust, then the extinc- Telescopio Nazionale Galileo (Canary Is- tion curve must be quite unusual: rela- lands). SDSS1048+46 was observed for tively flat at λ> 1700 A˚ and steeply rising a total of 3 hours, with a slit of 1.5′′ at shorter wavelengths. We can quantita- oriented along the parallactic angle. We tively derive the extinction curve by using used a grism covering the spectral region the equation Aλ = −2.5 log(Fobs/Fintr), 0.8 − 1.45µm. where Fobs is the observed spectrum and Fig. 1a shows the observed spectrum Fintr is the intrinsic spectrum. We avoided (solid line) smoothed to a lower resolution spectral regions contaminated by emis- for sake of clarity, and combined with a sion/absorption features by interpolating previous low resolution spectrum17 of the the continuum from the nearby regions. 26 full wavelength range 0.8 − 2.4µm. At The blend of FeII lines makes more un- the quasar’s redshift our data cover the certain the description of the continuum wavelength range 1200 < λrest < 3300A˚ in the spectral region between 2300A˚ and in the rest frame of the emitted radia- 3050A;˚ however, the latter spectral re- tion. The observed spectrum is much gion is not critical within the context of bluer than LoBAL quasars observed at this paper, since the most important as- z <4, whose average spectrum is shown pect is that the extinction curve must be with the dashed line13. In particular, rather flat in the region between 1700A˚ SDSS1048+46 is bluer than any known and 3300A,˚ and increase rapidly at λrest < LoBAL quasar13 at z <4. Since the red 1700A.˚ For the intrinsic spectrum we used shape of LoBAL quasars at z<4 is ascribed the non-BAL template obtained by the 13 to dust reddening, the much bluer slope of SLOAN survey (this choice is appropri- SDSS1048 already indicates a large varia- ate since non-BAL quasars at z∼6 have 17 tion of dust extinction and reddening from spectra similar to those at z<4) , with z < 4 to z ≈ 6. slopes ranging from α = −2.1 (the red- The continuum at λrest >1700 A˚ can dest slope compatible with our observed A SUPERNOVA ORIGIN FOR DUST IN A HIGH-REDSHIFT QUASAR 3 spectrum at λrest > 1700A)˚ to α = −2.5 of silicates (Mg2SiO4 and MgSiO3), amor- (only 1% of quasars have slopes bluer than phous carbon (AC), magnetite (Fe3O4) 13 this value ). The resulting extinction and corundum (Al2O3). The typical grain curve is shown in Fig. 2 (thick solid line sizes range between 5 A˚ to 0.1 µm, with and shaded region). As expected, the ex- smaller grains being predominantly com- tinction curve inferred for this quasar at posed of silicates and magnetite (sizes ≈5– z =6.2 is quite different with respect to 15 A)˚ and larger ones by amorphous car- the SMC curve which applies to quasars bon (sizes ≈ 100 − 200 A).˚ The pre- at z < 4. The dot-dashed line in Fig. 1b dicted grain properties for different Type- indicates the non-BAL template absorbed II SNe have then been averaged over the with the extinction curve inferred by us in stellar Initial Mass Function (IMF). We Fig.2, which nicely matches the observed adopted a Salpeter IMF, but even higher- spectrum (except for the emission and ab- mass weighted Larson-like IMFs22 do not < sorption lines, whose intensity and shape change significantly the results ( ∼ 2% in depend on the physics of the ionized gas). the extinction curve). The extinction A required to match 3000A˚ The SN dust extinction properties have the observed spectrum is in the range 0.4- been derived using the standard Mie the- 0.8 mag. ory for spherical grains. Grains made The extinction curve inferred from the of AC are the main contributors to ex- most distant LoBAL can also reproduce tinction. We used the optical properties the shape of the second most distant for AC produced in an inert atmosphere BAL SDSS1044-01, a High Ionization (ACAR23), which is appropriate for the BAL (HiBAL)17 at z =5.78. The lat- SN ejecta environment. Other important ter quasar presents much lower reddening contributors to extinction were found to 24,25 than SDSS1048-46 and therefore cannot be Mg2SiO4 and Fe3O4 grains . be used to provide tight constraints on the Fig.2 shows the resulting extinction extinction curve. Nonetheless, similarly to curves, which are in a much better agree- SDSS1048-46, it is characterized a rather ment with the observations than the usual blue continuum at λrest > 1700A˚ and a SMC curve. The extinction curves were reddening at λrest < 1700A,˚ which can be obtained for various initial stellar metal- nicely fitted by using the same extinction licities. The best agreement is found for −2 −4 curve derived above and shown in Fig. 2. the Z = 10 Z⊙ and 10 Z⊙ mod- In order to interpret the observations, els, although the other models do not dif- we have computed the SN dust extinc- fer strongly and are still within the ob- tion curve by using the model proposed by servational uncertainties.
Load more

Recommended publications
  • Quantum Detection of Wormholes Carlos Sabín
    www.nature.com/scientificreports OPEN Quantum detection of wormholes Carlos Sabín We show how to use quantum metrology to detect a wormhole. A coherent state of the electromagnetic field experiences a phase shift with a slight dependence on the throat radius of a possible distant wormhole. We show that this tiny correction is, in principle, detectable by homodyne measurements Received: 16 February 2017 after long propagation lengths for a wide range of throat radii and distances to the wormhole, even if the detection takes place very far away from the throat, where the spacetime is very close to a flat Accepted: 15 March 2017 geometry. We use realistic parameters from state-of-the-art long-baseline laser interferometry, both Published: xx xx xxxx Earth-based and space-borne. The scheme is, in principle, robust to optical losses and initial mixedness. We have not observed any wormhole in our Universe, although observational-based bounds on their abundance have been established1. The motivation of the search of these objects is twofold. On one hand, the theoretical implications of the existence of topological spacetime shortcuts would entail a challenge to our understanding of deep physical principles such as causality2–5. On the other hand, typical phenomena attributed to black holes can be mimicked by wormholes. Therefore, if wormholes exist the identity of the objects in the center of the galaxies might be questioned6 as well as the origin of the already observed gravitational waves7, 8. For these reasons, there is a renewed interest in the characterization of wormholes9–11 and in their detection by classical means such as gravitational lensing12, 13, among others14.
    [Show full text]
  • Active Galactic Nuclei: a Brief Introduction
    Active Galactic Nuclei: a brief introduction Manel Errando Washington University in St. Louis The discovery of quasars 3C 273: The first AGN z=0.158 2 <latexit sha1_base64="4D0JDPO4VKf1BWj0/SwyHGTHSAM=">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</latexit> <latexit sha1_base64="H7Rv+ZHksM7/70841dw/vasasCQ=">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</latexit> The power source of quasars • The luminosity (L) of quasars, i.e. how bright they are, can be as high as Lquasar ~ 1012 Lsun ~ 1040 W. • The energy source of quasars is accretion power: - Nuclear fusion: 2 11 1 ∆E =0.007 mc =6 10 W s g−
    [Show full text]
  • A Multimessenger View of Galaxies and Quasars from Now to Mid-Century M
    A multimessenger view of galaxies and quasars from now to mid-century M. D’Onofrio 1;∗, P. Marziani 2;∗ 1 Department of Physics & Astronomy, University of Padova, Padova, Italia 2 National Institute for Astrophysics (INAF), Padua Astronomical Observatory, Italy Correspondence*: Mauro D’Onofrio [email protected] ABSTRACT In the next 30 years, a new generation of space and ground-based telescopes will permit to obtain multi-frequency observations of faint sources and, for the first time in human history, to achieve a deep, almost synoptical monitoring of the whole sky. Gravitational wave observatories will detect a Universe of unseen black holes in the merging process over a broad spectrum of mass. Computing facilities will permit new high-resolution simulations with a deeper physical analysis of the main phenomena occurring at different scales. Given these development lines, we first sketch a panorama of the main instrumental developments expected in the next thirty years, dealing not only with electromagnetic radiation, but also from a multi-messenger perspective that includes gravitational waves, neutrinos, and cosmic rays. We then present how the new instrumentation will make it possible to foster advances in our present understanding of galaxies and quasars. We focus on selected scientific themes that are hotly debated today, in some cases advancing conjectures on the solution of major problems that may become solved in the next 30 years. Keywords: galaxy evolution – quasars – cosmology – supermassive black holes – black hole physics 1 INTRODUCTION: TOWARD MULTIMESSENGER ASTRONOMY The development of astronomy in the second half of the XXth century followed two major lines of improvement: the increase in light gathering power (i.e., the ability to detect fainter objects), and the extension of the frequency domain in the electromagnetic spectrum beyond the traditional optical domain.
    [Show full text]
  • Stellar Death: White Dwarfs, Neutron Stars, and Black Holes
    Stellar death: White dwarfs, Neutron stars & Black Holes Content Expectaions What happens when fusion stops? Stars are in balance (hydrostatic equilibrium) by radiation pushing outwards and gravity pulling in What will happen once fusion stops? The core of the star collapses spectacularly, leaving behind a dead star (compact object) What is left depends on the mass of the original star: <8 M⦿: white dwarf 8 M⦿ < M < 20 M⦿: neutron star > 20 M⦿: black hole Forming a white dwarf Powerful wind pushes ejects outer layers of star forming a planetary nebula, and exposing the small, dense core (white dwarf) The core is about the radius of Earth Very hot when formed, but no source of energy – will slowly fade away Prevented from collapsing by degenerate electron gas (stiff as a solid) Planetary nebulae (nothing to do with planets!) THE RING NEBULA Planetary nebulae (nothing to do with planets!) THE CAT’S EYE NEBULA Death of massive stars When the core of a massive star collapses, it can overcome electron degeneracy Huge amount of energy BAADE ZWICKY released - big supernova explosion Neutron star: collapse halted by neutron degeneracy (1934: Baade & Zwicky) Black Hole: star so massive, collapse cannot be halted SN1006 1967: Pulsars discovered! Jocelyn Bell and her supervisor Antony Hewish studying radio signals from quasars Discovered recurrent signal every 1.337 seconds! Nicknamed LGM-1 now called PSR B1919+21 BRIGHTNESS TIME NATURE, FEBRUARY 1968 1967: Pulsars discovered! Beams of radiation from spinning neutron star Like a lighthouse Neutron
    [Show full text]
  • Safeye Quasar 900 the New Safeye Quasar 900 Is an Open Path Detection System Which Provides Continuous Monitoring for Combustible Hydrocarbon Gases
    SafEye Quasar 900 The New SafEye Quasar 900 is an open path detection system which provides continuous monitoring for combustible hydrocarbon gases. It employs "spectral fingerprint" analysis of the atmosphere using the Differential Optical Absorption Spectroscopy (DOAS) technique. FEATURES & BENEFITS • Detects Hydrocarbon gases including methane, ethylene, propylene • Detection range: 4-200m in three different models (same detector different sources) • Built in event recorder – real time record of the last 100 events • Fast connection to Hand-Held for prognostic and diagnostic maintenance • Heated optics • Design to meet SIL2, per IEC61508 • Outputs: - 0-20mA - HART protocol for maintenance and asset managements - RS-485, Modbus Compatible The Quasar 900 consists of a Xenon Flash infrared transmitter and infrared receiver, separated over a • High reliability – MTBF minimum 100,000 hours line of sight from 13 ft (4m) up to 650 ft (200m) • User programmable via HART or RS-485 in extremely harsh environments where dust, fog, • 3 years warranty (10 years for the flash source) rain, snow or vibration can cause a high reduction of signal. • Ex approval: - Design to ATEX, IECEx per The Quasar 900 transmitter and receiver are both Ex II 2 (1) GD housed in a rugged, stainless steel, ATEX and IECEx approved enclosure. The main enclosure is EExd EEx de ia II C T5 flameproof with an integral, segregated, EExe - Design to FM, CSA per increased safety terminal section. Class I Div 1 Group B, C and D Class I, II Div 1 Group E, F and D The hand-held communication unit can be connected - Performance test: design to FM6325 and in-situ via the intrinsically safe approved data port EN50241-1 and 2 for prognostic and diagnostic maintenance.
    [Show full text]
  • 8. Active Galactic Nuclei. Radio Galaxies and Quasars
    8. ACTIVE GALACTIC NUCLEI. RADIO GALAXIES AND QUASARS This Section starts analyzing the phenomenon of extragalactic Active Galactic Nuclei. Here we will essentially discuss their low-photon-energy emissions, while in Sect. 9 we will expand on the high-photon-energy ones. 8.1 Active Galactic Nuclei: Generalities We know that normal galaxies constitute the majority population of cosmic sources in 12 the local universe. Although they may be quite massive (up to 10 M), they are not 11 44 typically very luminous (never more luminous than 10 Lʘ10 erg/sec). For this reason normal galaxies have remained hardly detectable at very large cosmic distances for long time, with recent advances mostly thanks to technological observational improvements. For several decades, since the ’60, the only detectable objects at large cosmic distances belonged to a completely different class of sources, which did not derive their energy from thermonuclear burning in stars. These are the Active Galactic Nuclei, for which we use the acronym AGN. The galaxies hosting them are called active galaxies. For their luminosity, Active Galactic Nuclei and Active Galaxies have plaid a key role in the development of cosmology, further to the fact that they make one of the most important themes of extragalactic astrophysics and High Energy Astrophysics. Apparently, the interest for the Active Galaxies as a population might seem modest, as in the local universe they make a small fraction of normal galaxies, as summarized in the following. There are four main categories of Active Galaxies and AGN: 1. galaxies with an excess of infrared emission and violent activity of star formation (starburst), selected in particular in the far-IR, the luminous (LIRG), ultra-luminous (ULIRG) and hyper-luminous (HYLIRG) galaxies: the 3 classes 11 12 13 have bolometric luminosities >10 L (LIRG), >10 L (ULIRG), >10 L (HYLIRG); 2.
    [Show full text]
  • 16.1 Quasars and Active Galactic Nuclei
    Quasars and Active Galactic Nuclei Ay1 – Lecture 16 16.1 Quasars and Active Galactic Nuclei: General Properties and Classification Quasars and Active Galactic Nuclei • Highly energetic manifestations in the nuclei of galaxies, powered by accretion onto supermassive massive black holes • Empirical classification schemes have been developed, on the basis of the spectra; but recently, various unification schemes have been developed (~ the same underlying phenomenon) • Evolve strongly in time, with the comoving densities of luminous ones increasing by ~ 103 from z ~ 0 to z ~ 2 • At z ~ 0, at least 30% of all galaxies show some sign of a nuclear activity; ~ 1% can be classified as Seyferts, and ~ 10-6 contain luminous quasars • We think that most or all non-dwarf galaxies contain SMBHs, and thus probably underwent at least one AGN phase AGN, an artist’s view Relativistic jet / illumination cone Central black hole Accretion disk Obscuring dusty torus Observable Properties of AGN • Emission over a broad range of frequencies, radio to γ-rays – Nonthermal radio or X-ray emission is a good way to find AGN – Generally bluer spectra than stars: “UV excess” – Colors unlike those of stars, especially when modified by the intergalactic absorption • Presence of strong, broad emission lines in their spectra 15 • Can reach large luminosities, up to ~ 10 L • Strong variability at all time scales – Implies small physical size of the emission region • Central engines unresolved • Undetectable proper motions due to a large distances All of these have been used to devise methods to discover AGN, and each method has its own limitations and selection effects Broad-Band Spectra of Quasars Radio Loud Radio Quiet UV-Optical Spectra of Quasars Strong, broad emission lines: Balmer lines of hydrogen Prominent lines of abundant ions Quasar Counts For the unobscured, Type 1 QSOs; they may be outnumbered by the obscured ones.
    [Show full text]
  • Quasar Catalogue for the Astrometric Calibration of the Forthcoming ILMT Survey
    J. Astrophys. Astr. (2020) 41:22 Ó Indian Academy of Sciences https://doi.org/10.1007/s12036-020-09642-xSadhana(0123456789().,-volV)FT3](0123456789().,-volV) Quasar catalogue for the astrometric calibration of the forthcoming ILMT survey AMIT KUMAR MANDAL1,4,*, BIKRAM PRADHAN2, JEAN SURDEJ3, C. S. STALIN4, RAM SAGAR4 and BLESSON MATHEW1 1Department of Physics, CHRIST (Deemed to be University), Hosur Road, Bangalore 560 029, India. 2Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263 001, India. 3Space Science, Technologies and Astrophysics Research (STAR) Institute, Universite´ de Lie`ge, Alle´edu6 Aouˆt 19c, 4000 Lie`ge, Belgium. 4Indian Institute of Astrophysics, Block II, Koramangala, Bangalore 560 034, India. E-mail: [email protected] MS received 27 May 2020; accepted 13 July 2020 Abstract. Quasars are ideal targets to use for astrometric calibration of large scale astronomical surveys as they have negligible proper motion and parallax. The forthcoming 4-m International Liquid Mirror Tele- scope (ILMT) will survey the sky that covers a width of about 270. To carry out astrometric calibration of the ILMT observations, we aimed to compile a list of quasars with accurate equatorial coordinates and falling in the ILMT stripe. Towards this, we cross-correlated all the quasars that are known till the present date with the sources in the Gaia-DR2 catalogue, as the Gaia-DR2 sources have position uncertainties as small as a few milli arcsec (mas). We present here the results of this cross-correlation which is a catalogue of 6738 quasars that is suitable for astrometric calibration of the ILMT fields.
    [Show full text]
  • Quasar Jet Emission Model Applied to the Microquasar GRS 1915+105
    A&A 415, L35–L38 (2004) Astronomy DOI: 10.1051/0004-6361:20040010 & c ESO 2004 Astrophysics Quasar jet emission model applied to the microquasar GRS 1915+105 M. T¨urler1;2, T. J.-L. Courvoisier1;2,S.Chaty3;4,andY.Fuchs4 1 INTEGRAL Science Data Centre, ch. d’Ecogia 16, 1290 Versoix, Switzerland 2 Observatoire de Gen`eve, ch. des Maillettes 51, 1290 Sauverny, Switzerland Letter to the Editor 3 Universit´e Paris 7, 2 place Jussieu, 75005 Paris, France 4 Service d’Astrophysique, DSM/DAPNIA/SAp, CEA/Saclay, 91191 Gif-sur-Yvette, Cedex, France Received 18 December 2003 / Accepted 14 January 2004 Abstract. The true nature of the radio emitting material observed to be moving relativistically in quasars and microquasars is still unclear. The microquasar community usually interprets them as distinct clouds of plasma, while the extragalactic com- munity prefers a shock wave model. Here we show that the synchrotron variability pattern of the microquasar GRS 1915+105 observed on 15 May 1997 can be reproduced by the standard shock model for extragalactic jets, which describes well the long-term behaviour of the quasar 3C 273. This strengthens the analogy between the two classes of objects and suggests that the physics of relativistic jets is independent of the mass of the black hole. The model parameters we derive for GRS 1915+105 correspond to a rather dissipative jet flow, which is only mildly relativistic with a speed of 0:60 c. We can also estimate that the shock waves form in the jet at a distance of about 1 AU from the black hole.
    [Show full text]
  • Formation of Supermassive Black Holes
    Formation of Supermassive Black Holes by Stefan Taubenberger 1 Galaxies with BHs in their center 2 Centaurus A 3 Centaurus A 4 M87 / Virgo A 5 M87 / Virgo A 6 Index 1) Observational constraints Quasars found at z~6 Quasar number density σ MBH - relation Recent observation of Black Hole binaries Quiescent SMBHs 2) 3 basic scenarios of SMBH formation Collapse of a gas cloud or a supermassive star to a SMBH in the early universe Runaway growth by accretion Mergers of two Black Holes 3) One possible model of SMBH formation Observation Scenarios possible model 7 Quasars at z~6 z = 5,8 Sloan Digital Sky Survey (SDSS) 2002: quasar at z = 5,8 Quasars Ù massive accreting BHs z = 4,75 First massive BHs must have existed 1 Gyr after the Big Bang ⇨ very rapid formation process required Observation: z~6 quasars Scenarios possible model 8 Quasar number density Quasar density peaks at z ~ 2 (~ 3 billion years after Big Bang) since then decrease in quasar density: Seyfert galaxies (active galaxies, but less luminous than quasars) show different behaviour: maximum shifted to lower redshifts (z ~ 1) maximum is higher ⇨ Seyfert galaxies more common than quasars What is the physical difference? SMBH formation model should explain both phenomena Observation: number dens. Scenarios possible model 9 Quasar number density Quasar density peaks at z ~ 2 (~ 3 billion years after Big Bang) since then decrease in quasar density: Seyfert galaxies (active galaxies, but less luminous than quasars) show different behaviour: maximum shifted to lower redshifts (z ~ 1) maximum is higher ⇨ Seyfert galaxies more common than quasars What is the physical difference? SMBH formation model Hasinger et al.
    [Show full text]
  • Quasar-Galaxy Associations
    Mon Not R Astron So c ? Quasargalaxy asso ciations P A Thomas R L Webster and M J Drinkwater Astronomy Centre MAPS University of Sussex Brighton BN QH School of Physics University of Melbourne Parkvil le Victoria Australia AngloAustralian Observatory Coonabarabran NSW Australia August ABSTRACT There is controversy ab out the measurement of statistical asso ciations b etween bright quasars and faint presumably foreground galaxies We lo ok at the distribution of galax ies around an unbiased sample of bright mo derate redshift quasars using a new statistic based on the separation of the quasar and its nearest neighbour galaxy We nd a signicant excess of close neighbours at separations less than ab out arcsec which we attribute to the magnication by gravitational lensing of quasars which would otherwise b e to o faint to b e included in our sample Ab out one quarter to one third of the quasars are so aected although the allowed error in this fraction is large Key words quasars general gravitational lensing signicant excess of galaxies near mo derately high red INTRODUCTION shift quasars Tyson Webster et al Fugmann In this pap er we lo ok at the asso ciation b etween quasars and and Hintzen Romanishin Valdes How foreground galaxies We nd a signicant excess over that ever some more recent studies eg Crampton McClure exp ected from a random distribution which we interpret as Fletcher and Yee Filipp enko Tang claim no b eing due to gravitational lensing ie many of the quasars statistical excess though quantitative
    [Show full text]
  • From Quasars to Microquasars S
    From quasars to microquasars jetted AGN stellar binaries 8 9 BH masses: 10 -10 Msun duty cycles: 107 yrs Radio Luminosity BH masses: 10s Msun duty cycles: month-to-yrs 28-32 Lradio~10 erg/s Mass/variability timescales Jet Flavors in Microquasars compact, persistent transient, relativistic large scale jets, hot spots & radio lobes/ radio jets (~10 AU) radio jets (~100s AU) (up to~10s pc) cavities CygX-1 GRS1915+105 1E 140.7-2942Tetarenko+’18 CygX-1 Stirling+’01 Russell+’07 Mirabel & Rodriguez’94 Mirabel & Rodriguez+’92 milli-arcsec arcsec arcmin ->degree accretion & ejection jet power & radio duty cycle relation interaction with the ISM 2 Jets through the BH mass scale Circus X-1 Sell+’10 ljet~0.5 pc jets in 10 Msun BH 2 rg=2MBHG/c ljet/rg ljet~5-50 Mpc jets in 108-9 Msun BH as observing Mpc jets of a radio galaxy moving, varying and changing morphology!(*) (*: jet’s thrust ratio is not the same, Heinz+2013) A Galactic perspective: (micro)quasar large-scale X-ray jets Giulia Migliori (DIFA, INAF-IRA) S.Corbel, J. Tomsick, P. Kaaret, R. Fender, T. Tzioumis, M. Coriat, J. Orosz XTE J1550-564 large scale jets Corbel+’02 Low Mass X-ray Binary: • BH mass: 9.1+/-0.6 Msun (Orosz+’11); • distance: 4.4+/-0.6 kpc; • inclination: 75+/-4 degree; • September 1998: X-ray outburst followed by the detection of relativistic compact jets (vapp~1.7c, Hannikainen+09); Corbel'et'al.'2002' Discovery of large scale (~0.5pc) decelerating jets following the 1998 outburst 5 XTE J1550-564 large scale jets Dynamical Model: the jets propagate unseen in an under-dense ISM cavity and become visible when they impact the cavity’s boundaries (Wang ’03; Hao&Zhang ’09, Steiner+’12).
    [Show full text]