DOCSLIB.ORG

A Galaxy Rapidly Forming Stars 700 Million Years After the Big Bang At

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Galaxy Rapidly Forming Stars 700 Million Years After the Big Bang At SUPPLEMENTARY INFORMATION doi:10.1038/nature12657 • R P(z>[zsample − 2])dz ≥ 0.5 • zbest >zsample − 2 1Sample Selection • R P(z>[zsample − 2])dz ≥ 0.5 Our sample of high-redshift galaxies in the GOODS-North field 2 • χ• < 60 − was selected using an updated version of the criteria presented in pre- zbest >zsample 2 1Sample15,22 Selection vious papers; the full sample will be published in Finkelstein et al. 2 Our sample of high-redshift galaxies in the GOODS-North fieldThese are• χ very< similar60 to the criteria used in our previous publications, in prep.was selected These papers using can an updated be consulted version for of more the criteria details, presented but here we in pre-and they have been shown to produce samples which match up very 15,22 15 brieflyvious recap papers; our process.the full sample will be published in Finkelstein et al.wellThese with available are very similarspectroscopic to the criteria redshifts used at z< in our7. previous publications, 28 Thein prep. optical These imaging papers comes canfrom be consulted the GOODS for more survey, details,and webut used here we Theand selectedthey have sources been shownwere visually to produce inspected samples to reject which artifacts match such up very 15 the v2.0briefly ACS recap imaging, our process. consisting of mosaics in the F435W, F606W, as diffractionwell with spikesavailable and spectroscopic oversplit regions redshifts of bright at z< galaxies.7. Addition- 28 F775WThe and optical F850LP imaging filters. comes The near-infraredfrom the GOODS data survey, comes fromand we the usedally, theThe colors selected of galaxy sources candidates were visually were inspected compared to to reject the artifactsexpected such CANDELSthe v2.0 survey, ACS imaging, and we used consisting the CANDELS of mosaics team’s in the early F435W, data prod- F606W,colorsas diffractionof M, L and spikes T-dwarf and stars, oversplit and regionsany sources of bright with galaxies. star-like colors Addition- uctsF775W (v0.1) in and the F850LP F105W, filters.F125WThe and F160W near-infrared filters. data The comes CANDELS from thewhichally, were the also colors unresolved of galaxy were candidates rejected from were the compared sample. to Finally, the expected the surveyCANDELS obtained survey, data atand two we depths, used denotedthe CANDELS as “WIDE” team’s and early “DEEP”. data prod-opticalcolors bands of M, were L andalso T-dwarf inspected stars, to ensure and any that sources they visually with star-like appeared colors Theucts imaging (v0.1) used in thehere F105W, consists F125W of the full and depth F160W in the filters. Northeast The CANDELS WIDE to containwhich were no significant also unresolved (>1.5σ were) flux rejected (in practice, from the sources sample. with Finally, sig- the region, and about half of the full depth of the DEEP region. The 5σ survey obtained data at two depths,′′ denoted as “WIDE” and “DEEP”.nificantoptical optical bands flux were would also have inspected already to beenensure rejected that they by visually our selection appeared limitingThe magnitudes,imaging used measured here consists in 0.4 of the-diameter full depth apertures, in the Northeast for the ACS WIDEcriteria).to contain Our final no significant galaxy samples (>1.5 consistσ) flux of (in 175 practice, candidate sources galaxies with at sig- bandsregion, are: 28.1, and about 28.3, 27.8 half ofand the 27.7 full mag, depth respectively of the DEEP (all region. magnitudes The 5σz ≈ 6, 85 at z ≈ 7 and 25 at z ≈ 8. 29 ′′ nificant optical flux would have already been rejected by our selection are quotedlimiting in magnitudes, the AB system measured). For in the 0.4 three-diameter WFC3 apertures, bands, the for exist- the ACS criteria). Our final galaxy samples consist of 175 candidate galaxies at σ ing DEEPbandsare: 5 depths 28.1, 28.3, are 27.9, 27.8 27.9 and and27.7 27.7 mag, mag, respectively while for (all the magnitudes WIDE 2z Spectroscopic≈ 6, 85 at z ≈ 7 and Followup 25 at z ≈ Sample8. region, the depths are 27.4, 27.4 and29 27.3 mag, respectively. Addition- are quoted in the AB system ). For the three WFC3 bands, the exist- From our parent sample of candidate galaxies, we selected those ally, we add to ourσ analysis new, extremely deep, optical data obtained ing DEEP 5 depths are 27.9, 27.9 and 27.7 mag, while for the WIDEfor spectroscopic2 Spectroscopic followup with Followup MOSFIRE Sample via two criteria: 1) appar- withregion, ACS in the parallel depths to are the 27.4, CANDELS 27.4 and observations. 27.3 mag, respectively. These data Addition- were ent F160WFrom magnitude, our parent and sample 2) maximizing of candidateR galaxies,P(7.0 <z< we selected8.2)dz those obtainedally, we in the add F814W to our analysis filter, and new, have extremely an exposure deep, timeoptical of data 57,000 obtained s (whichfor spectroscopic corresponds to followup the redshift with rangeMOSFIRE placing via Ly twoα criteria:in the MOS- 1) appar- at thewith position ACS in of parallel z8 GND to5296, the CANDELS showing no observations. detectable flux These within data a were ′′ FIREentY F160W-band grating). magnitude, We and first 2) prioritized maximizing basedR P on(7 brightness,.0 <z< and8.2)dz 0.4 obtained-diameter in aperture the F814W 5σ depth filter, of and 28.8. have We an created exposure photometry time of cata- 57,000 s 30 then(which within corresponds each magnitude to the bin, redshift we prioritized range placing based Lyonα thein highest the MOS- logsat with the the position Source of Extractor z8 GND software,5296, showingusing no a weighted detectable sum flux of within the a ′′ valueFIRE of theY -band integral grating). defined We above. first We prioritized input these based catalogs on brightness, into the and F125W0.4 and-diameter F160W aperture images 5 asσ depth the detection of 28.8. image. We created We measured photometry col- cata- F1 MAGMAthen within software each, magnitude which was bin, created we by prioritized the MOSFIRE based team on the to de-highest ors inlogs small with elliptical the Source apertures, Extractor setting software, the Kron30 using aperture a weighted parameters sum to of the signvalue mask of configurations. the integral defined The software above. searches We input a large these (user-defined) catalogs into the KronF125Wfact=1.2 and and F160W min imagesradius= as1.7. the Aperture detection corrections image. We were measured mea- col- F1 parameterMAGMA space software in both right, which ascension, was created declination by the MOSFIRE and position team an- to de- suredors in in the small F160W elliptical band apertures, by comparing setting the the flux Kron in this aperture small parameters aperture to gle tosign maximize mask configurations. the total priority The of software sources. searches We designed a large two (user-defined) masks: to thatKron in thefact default=1.2 and MAG minAUTOradius= aperture,1.7. Aperture which is corrections representative were of mea- GOODSNparameterMask1, space with in both a position right ascension, angle of 34 declination degrees, containing and position 24 an- the totalsured flux. in the Photometry F160W band was by performed comparing on the the flux DEEP inthis andsmall WIDE aperture re- candidategle to maximizehigh-redshift the galaxies, total priority and of GOODSN sources. WeMask2, designed with twoa posi- masks: gionsto separately. that in the Photometry default MAG errorsAUTO were aperture, obtained which by providing is representative Source of tionGOODSN angle of −9.5Mask1, degrees, with containing a position 19. angle of 34 degrees, containing 24 Extractorthe total with flux. accurate Photometry RMS images. was performed on the DEEP and WIDE re- candidate high-redshift galaxies, and GOODSN Mask2, with a posi- Nogions RMS separately. map was Photometry available for errors the were F814W obtained data, butby providing we followed Source tion angle of −9.5 degrees, containing 19. theExtractor same procedures with accurate usedRMS to calibrate images. noise maps for the standard 3 Observations and Data Reduction 31 CANDELSNo RMS HST mapdata was products available. We for measured the F814W the data, RMS but and we auto- followed Our observations took place on UT 18-19 April 2013 under clear, Y correlationthe same function procedures of the used background to calibrate noise noise near mapsthe position for the of standard our mostly3 photometric Observations conditions. and Data We used Reduction MOSFIRE with the -band 31 grating, which observes ∼0.97 – 1.12 µm, and set the slit widths to object,CANDELS after masking HST outdata sources. products We. scaled We measured the correlation-corrected the RMS and auto- ′′ Our observations took place on UT 18-19 April 2013 under clear, RMScorrelation to the number function of pixels of the in thebackground elliptical noisephotometry near the aperture, position find- of our0.7 mostly. We observed photometric each conditions. configuration We for used one MOSFIRE night, taking with 180 the Y sec-band ing a total 1σ F814W flux uncertainty of 5 nJy. This is a factor of exposuresgrating, with which an observesABAB dither∼0.97 pattern, – 1.12 withµm, dither and set positions the slit widthssepa- to object, after masking out sources. We scaled the correlation-corrected ′′ ′′ aboutRMS 3× todeeper the number than the of GOODSpixels in theF775W elliptical or F850LP photometry imaging aperture, at this find-rated0.7 by. 2.5 We, yielding observed a each total exposureconfiguration time for of 5.6 one hr night, for the taking first con- 180 sec position. These F814Wσ data were not available at the time of our ob- figurationexposures and with4.45 anhr for ABAB the second. dither pattern, The data with were dither reduced positions using sepa- ing a total 1 F814W flux uncertainty of 5 nJy.
Load more

Recommended publications
  • A Dusty, Normal Galaxy in the Epoch of Reionization
    A dusty, normal galaxy in the epoch of reionization Darach Watson1, Lise Christensen1, Kirsten Kraiberg Knudsen2, Johan Richard3, Anna Gallazzi4,1, and Michał Jerzy Michałowski5 Candidates for the modest galaxies that formed most of the stars in the early universe, at redshifts z > 7, have been found in large numbers with extremely deep restframe-UV imaging1. But it has proved difficult for existing spectrographs to characterise them in the UV2,3,4. The detailed properties of these galaxies could be measured from dust and cool gas emission at far-infrared wavelengths if the galaxies have become sufficiently enriched in dust and metals. So far, however, the most distant UV-selected galaxy detected in dust emission is only at z = 3.25, and recent results have cast doubt on whether dust and molecules can be found in typical galaxies at this early epoch6,7,8. Here we report thermal dust emission from an archetypal early universe star-forming galaxy, A1689-zD1. We detect its stellar continuum in spectroscopy and determine its redshift to be z = 7.5±0.2 from a spectroscopic detection of the Lyα break. A1689-zD1 is representative of the star-forming population during reionisation9, with a total star- –1 formation rate of about 12 M yr . The galaxy is highly evolved: it has a large stellar mass, and is heavily enriched in dust, with a dust-to-gas ratio close to that of the Milky Way. Dusty, evolved galaxies are thus present among the fainter star-forming population at z > 7, in spite of the very short time since they first appeared.
    [Show full text]
  • And Ecclesiastical Cosmology
    GSJ: VOLUME 6, ISSUE 3, MARCH 2018 101 GSJ: Volume 6, Issue 3, March 2018, Online: ISSN 2320-9186 www.globalscientificjournal.com DEMOLITION HUBBLE'S LAW, BIG BANG THE BASIS OF "MODERN" AND ECCLESIASTICAL COSMOLOGY Author: Weitter Duckss (Slavko Sedic) Zadar Croatia Pусскй Croatian „If two objects are represented by ball bearings and space-time by the stretching of a rubber sheet, the Doppler effect is caused by the rolling of ball bearings over the rubber sheet in order to achieve a particular motion. A cosmological red shift occurs when ball bearings get stuck on the sheet, which is stretched.“ Wikipedia OK, let's check that on our local group of galaxies (the table from my article „Where did the blue spectral shift inside the universe come from?“) galaxies, local groups Redshift km/s Blueshift km/s Sextans B (4.44 ± 0.23 Mly) 300 ± 0 Sextans A 324 ± 2 NGC 3109 403 ± 1 Tucana Dwarf 130 ± ? Leo I 285 ± 2 NGC 6822 -57 ± 2 Andromeda Galaxy -301 ± 1 Leo II (about 690,000 ly) 79 ± 1 Phoenix Dwarf 60 ± 30 SagDIG -79 ± 1 Aquarius Dwarf -141 ± 2 Wolf–Lundmark–Melotte -122 ± 2 Pisces Dwarf -287 ± 0 Antlia Dwarf 362 ± 0 Leo A 0.000067 (z) Pegasus Dwarf Spheroidal -354 ± 3 IC 10 -348 ± 1 NGC 185 -202 ± 3 Canes Venatici I ~ 31 GSJ© 2018 www.globalscientificjournal.com GSJ: VOLUME 6, ISSUE 3, MARCH 2018 102 Andromeda III -351 ± 9 Andromeda II -188 ± 3 Triangulum Galaxy -179 ± 3 Messier 110 -241 ± 3 NGC 147 (2.53 ± 0.11 Mly) -193 ± 3 Small Magellanic Cloud 0.000527 Large Magellanic Cloud - - M32 -200 ± 6 NGC 205 -241 ± 3 IC 1613 -234 ± 1 Carina Dwarf 230 ± 60 Sextans Dwarf 224 ± 2 Ursa Minor Dwarf (200 ± 30 kly) -247 ± 1 Draco Dwarf -292 ± 21 Cassiopeia Dwarf -307 ± 2 Ursa Major II Dwarf - 116 Leo IV 130 Leo V ( 585 kly) 173 Leo T -60 Bootes II -120 Pegasus Dwarf -183 ± 0 Sculptor Dwarf 110 ± 1 Etc.
    [Show full text]
  • The Early Universe Transcript
    The Early Universe Transcript Date: Wednesday, 4 February 2015 - 1:00PM Location: Museum of London 04 February 2015 The Early Universe Professor Carolin Crawford In my previous lectures I have discussed both the earliest glimpse of the Universe available to us, the cosmic microwave background, and the wide variety of astronomical sources that we observe all around us in the present day. Today’s talk is an attempt to join the dots between these two extremes: how do we move from an almost completely smooth distribution of matter when Universe was only 380,000 years old, to the complexity of stars, planets, gas clouds, galaxies and even larger scale structure? Galaxies don’t just simply appear shortly after the Big Bang, but they take tens of millions of years (at least) to form; and then they continue to change and evolve. Today’s topic is observational cosmology – the study of the most remote parts of the cosmos. This is a major growth area in astrophysics, where huge advances in our understanding have been made over the last 15-20 years, primarily due to cutting-edge advances in the design of the telescopes and their adaptive optics. What was this very early Universe like? What happened after the release of the cosmic microwave background light? What did the very first stars and the first galaxies look like? And what do they tell us about the history of galaxies like our own? Recombination Immediately after the Big Bang, the Universe was extremely hot and dense. After 380,000 years, it had expanded and cooled sufficiently for the elementary particles to join together and form the very first atoms.
    [Show full text]
  • Arxiv:2009.10092V2 [Astro-Ph.GA] 3 Dec 2020
    DRAFT VERSION DECEMBER 4, 2020 Typeset using LATEX twocolumn style in AASTeX62 Texas Spectroscopic Search for Lyα Emission at the End of Reionization. III. the Lyα Equivalent-width Distribution and Ionized Structures at z > 7 INTAE JUNG,1, 2, 3, 4 STEVEN L. FINKELSTEIN,4 MARK DICKINSON,5 TAYLOR A. HUTCHISON,6, 7 REBECCA L. LARSON,4 CASEY PAPOVICH,6, 7 LAURA PENTERICCI,8 AMBER N. STRAUGHN,1 YICHENG GUO,9 SANGEETA MALHOTRA,1, 10 JAMES RHOADS,1, 10 MIMI SONG,11 VITHAL TILVI,10 AND ISAK WOLD1 1Astrophysics Science Division, Goddard Space Flight Center, Greenbelt, MD 20771, USA 2Department of Physics, The Catholic University of America, Washington, DC 20064, USA 3Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD 20771 4Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA 5NSF’s National Optical-Infrared Astronomy Research Laboratory, Tucson, AZ 85719, USA 6Department of Physics and Astronomy, Texas A&M University, College Station, TX, 77843-4242 USA 7George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX, 77843-4242 USA 8INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00078, Monteporzio Catone, Italy 9Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA 10School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85287, USA 11Department of Astronomy, University of Massachusetts, Amherst, MA 01002, USA (Published 2020 November 27 in ApJ) ABSTRACT Lyα emission from galaxies can be utilized to characterize the ionization state in the intergalactic medium (IGM). We report our search for Lyα emission at z > 7 using a comprehensive Keck/MOSFIRE near-infrared spectroscopic dataset, as part of the Texas Spectroscopic Search for Lyα Emission at the End of Reionization Survey.
    [Show full text]
  • Effects of Rotation Arund the Axis on the Stars, Galaxy and Rotation of Universe* Weitter Duckss1
    Effects of Rotation Arund the Axis on the Stars, Galaxy and Rotation of Universe* Weitter Duckss1 1Independent Researcher, Zadar, Croatia *Project: https://www.svemir-ipaksevrti.com/Universe-and-rotation.html; (https://www.svemir-ipaksevrti.com/) Abstract: The article analyzes the blueshift of the objects, through realized measurements of galaxies, mergers and collisions of galaxies and clusters of galaxies and measurements of different galactic speeds, where the closer galaxies move faster than the significantly more distant ones. The clusters of galaxies are analyzed through their non-zero value rotations and gravitational connection of objects inside a cluster, supercluster or a group of galaxies. The constant growth of objects and systems is visible through the constant influx of space material to Earth and other objects inside our system, through percussive craters, scattered around the system, collisions and mergers of objects, galaxies and clusters of galaxies. Atom and its formation, joining into pairs, growth and disintegration are analyzed through atoms of the same values of structure, different aggregate states and contiguous atoms of different aggregate states. The disintegration of complex atoms is followed with the temperature increase above the boiling point of atoms and compounds. The effects of rotation around an axis are analyzed from the small objects through stars, galaxies, superclusters and to the rotation of Universe. The objects' speeds of rotation and their effects are analyzed through the formation and appearance of a system (the formation of orbits, the asteroid belt, gas disk, the appearance of galaxies), its influence on temperature, surface gravity, the force of a magnetic field, the size of a radius.
    [Show full text]
  • Interpreting the Spitzer/IRAC Colours of 7 ≤ Z ≤ 9 Galaxies: Distinguishing Between Line Emission and Starlight Using ALMA
    MNRAS 497, 3440–3450 (2020) doi:10.1093/mnras/staa2085 Advance Access publication 2020 July 16 Interpreting the Spitzer/IRAC colours of 7 ≤ z ≤ 9 galaxies: distinguishing between line emission and starlight using ALMA G. W. Roberts-Borsani ,1,2‹ R. S. Ellis2 and N. Laporte3,4,2 1Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095, USA 2Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK 3Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 4 Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK Downloaded from https://academic.oup.com/mnras/article/497/3/3440/5872501 by UCL, London user on 09 December 2020 Accepted 2020 July 13. Received 2020 June 30; in original form 2020 January 7 ABSTRACT Prior to the launch of JWST, Spitzer/IRAC photometry offers the only means of studying the rest-frame optical properties of z >7 galaxies. Many such high-redshift galaxies display a red [3.6]−[4.5] micron colour, often referred to as the ‘IRAC excess’, which has conventionally been interpreted as arising from intense [O III]+H β emission within the [4.5] micron bandpass. An appealing aspect of this interpretation is similarly intense line emission seen in star-forming galaxies at lower redshift as well as the redshift-dependent behaviour of the IRAC colours beyond z ∼ 7 modelled as the various nebular lines move through the two bandpasses. In this paper, we demonstrate that, given the photometric uncertainties, established stellar populations with Balmer (4000 Å rest frame) breaks, such as those inferred at z>9 where line emission does not contaminate the IRAC bands, can equally well explain the redshift-dependent behaviour of the IRAC colours in 7 z 9 galaxies.
    [Show full text]
  • Cover Illustration by JE Mullat the BIG BANG and the BIG CRUNCH
    Cover Illustration by J. E. Mullat THE BIG BANG AND THE BIG CRUNCH From Public Domain: designed by Luke Mastin OBSERVATIONS THAT SEEM TO CONTRADICT THE BIG BANG MODEL WHILE AT THE SAME TIME SUPPORT AN ALTERNATIVE COSMOLOGY Forrest W. Noble, Timothy M. Cooper The Pantheory Research Organization Cerritos, California 90703 USA HUBBLE-INDEPENDENT PROCEDURE CALCULATING DISTANCES TO COSMOLOGICAL OBJECTS Joseph E. Mullat Project and Technical Editor: J. E. Mullat, Copenhagen 2019 ISBN‐13 978‐8740‐40‐411‐1 Private Publishing Platform Byvej 269 2650, Hvidovre, Denmark [email protected] The Postulate COSMOLOGY THAT CONTRADICTS THE BIG BANG THEORY The Standard and The Alternative Cosmological Models, Distances Calculation to Galaxies without Hubble Constant For the alternative cosmological models discussed in the book, distances are calculated for galaxies without using the Hubble constant. This proc‐ ess is mentioned in the second narrative and is described in detail in the third narrative. According to the third narrative, when the energy den‐ sity of space in the universe decreases, and the universe expands, a new space is created by a gravitational transition from dark energy. Although the Universe develops on the basis of this postulate about the appear‐ ance of a new space, it is assumed that matter arises as a result of such a gravitational transition into both new dark space and visible / baryonic matter. It is somewhat unimportant how we describe dark energy, call‐ ing it ether, gravitons, or vice versa, turning ether into dark energy. It should be clear to everyone that this renaming does not change the es‐ sence of this gravitational transition.
    [Show full text]
  • Download This PDF File
    The Processes of Violent Disintegration and Natural Creation of Matter in the Universe Weitter Duckss Independent Researcher, Zadar, Croatia [email protected] Abstract: This article completes the circle of presenting the process of the constant growth of objects and systems and the topics to complete it consist of the visible matter violent disintegration and its re-creation inside the Universe. A constant process of the visible matter disintegration is presented as the end of the process, the proportions of which are gigantic, and the creation of the visible matter as the beginning of it. The disintegration of particles disturbs the balance of the Universe's wholeness; despite the enormous loss of the visible matter, the Universe is constantly growing. After having postponed it for a while, this article discusses the age of objects and the Universe as a consequence of the process of the constant matter growth. The acquired results are completely different from those, offered by the renowned experts of the time. Keywords: disintegration of matter; particle formation; the age of the Universe I. Introduction The goal of the article is to unite the total processes of the constant matter growth inside the Universe, based on the independent research, the use of databases of generally accepted, easily verifiable evidence for the broadest community of readers. This article is a summary of the materials inside the process of the constant matter gathering, with the articles (Yukawa, 1935), (Duckss, 2019), (Duckss, 2018), and (Duckss, 2018) due to gravity or the law of universal gravitation. The disintegration of matter is a process of turning the visible matter into the invisible matter and energy and it exists in the whole of the Universe.
    [Show full text]
  • Direct Constraints on UV Attenuation, Dust- Obscured Star Formation, and Dust Mass of Z=6.5-7.5 Galaxies
    Direct constraints on UV attenuation, dust- obscured star formation, and dust mass of z=6.5-7.5 galaxies! Daniel Schaerer (Geneva Observatory, CNRS)! Fréderic Boone (IRAP, Toulouse)! Other collaborators: M. Zamojski, M. Dessauges-Zavadsky, J. Staguhn, S. Finkelstein, F. Combes! ! • Introduction, motivation! • New constraints on z>6 star-forming galaxies! • Conclusions! Schaerer et al. 2014, A&A in press; arXiv:1407.5793! de Barros, Schaerer, Stark, 2014, A&A 563, A81! Schaerer & de Barros 2014, in prep! from the ratio of FIR to observed (uncorrected) FUV luminosity densities (Figure 8) as a function of redshift, using FUVLFs from Cucciati et al. (2012) and Herschel FIRLFs from Gruppioni et al. (2013). At z<2, these estimates agree reasonably well with the measure- ments inferred from the UV slope or from SED fitting. At z>2, the FIR/FUV estimates have large uncertainties owing to the similarly large uncertainties required to extrapolate the observed FIRLF to a total luminosity density. The values are larger than those for the UV-selected surveys, particularly when compared with the UV values extrapolated to very faint luminosities. Although galaxies with lower SFRs may have reduced extinction, purely UV-selected samples at high redshift may also be biased against dusty star-forming galaxies. As we noted above, a robust census for star-forminggalaxiesatz ! 2selected on the basis of dust emission alone does not exist, owing to thesensitivitylimitsofpast and present FIR and submillimeter observatories. Accordingly, the total amount of star formation that is missed from UV surveys at such high redshifts remains uncertain. Introduction! Cosmic star formation rate history! ! review of Madau & Dickinson (2014)! Figure 9: The history of cosmic star formation from (top right panel) FUV, (bottom right panel) IR, Majorand (left unknowns panel) FUV+IR rest-frame: ! measurements.
    [Show full text]
  • How Reading Difficulty Influences Mind-Wandering
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Waterloo's Institutional Repository How Reading Difficulty Influences Mind-Wandering: The Theoretical Importance of Measuring Interest by Noah Forrin A thesis presented to the University of Waterloo in fulfilment of the thesis requirement for the degree of Doctor of Philosophy in Psychology Waterloo, Ontario, Canada, 2016 © Noah Forrin 2016 i Author’s Declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract In many situations, increasing task difficulty decreases thoughts that are unrelated to the task (i.e., mind-wandering; see Smallwood & Schooler, 2006, for a review). However, Feng, D’Mello, and Graesser (2013) recently reported a discrepant finding in the context of reading. They showed that increasing the objective reading difficulty of passages (by decreasing word frequency and complicating sentence structure) actually increased mind-wandering. The primary goal of this work was to gain insight into the mechanism that drives this positive relation between objective reading difficulty and mind-wandering. This effect is investigated over three chapters. Chapter 1 demonstrates that the effect of objective difficulty on mind-wandering is confounded by differences in passage section-length between easy and hard passages when they are presented one sentence at a time. Chapter 2 more broadly explores the possibility that distinctive processing influences subjective impressions of passage difficulty and interest (which may consequently influence mind-wandering).
    [Show full text]
  • Early Galaxy Formation and Its Large-Scale Effects
    Early galaxy formation and its large-scale effects Pratika Dayal1 Kapteyn Astronomical Institute, Rijksuniversiteit Groningen, Landleven 12, Groningen, 9717 AD, The Netherlands Andrea Ferrara2 Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, 56126, Italy Abstract Galaxy formation is at the heart of our understanding of cosmic evolution. Although there is a consensus that galaxies emerged from the expanding matter background by gravitational instability of primordial fluctuations, a number of additional physical processes must be understood and implemented in theoretical models before these can be reliably used to interpret observations. In parallel, the astonishing recent progresses made in detecting galaxies that formed only a few hundreds of million years after the Big Bang is pushing the quest for more sophisticated and detailed studies of early structures. In this review, we combine the information gleaned from different theoretical models/studies to build a coherent picture of the Universe in its early stages which includes the physics of galaxy formation along with the impact that early structures had on large-scale processes as cosmic reionization and metal enrichment of the intergalactic medium. Keywords: High-redshift - intergalactic medium - galaxy formation - first stars - reionization - cosmology:theory Contents 1 Galaxy formation: a brief historical perspective 6 2 Cosmic evolution in a nutshell 12 3 The cosmic scaffolding: dark matter halos 16 arXiv:1809.09136v2 [astro-ph.GA] 23 Nov 2018 3.1 The standard cosmological model . 16 3.2 The start: linear perturbation theory . 19 3.3 Nonlinear collapse and hierarchical assembly of dark matter halos . 20 4 Basic physics of galaxy formation 26 4.1 Physical ingredients .
    [Show full text]
  • New Constraints on Dust Emission and UV Attenuation of Z = 6.5–7.5 Galaxies from Millimeter Observations
    A&A 574, A19 (2015) Astronomy DOI: 10.1051/0004-6361/201424649 & c ESO 2015 Astrophysics New constraints on dust emission and UV attenuation of z = 6.5–7.5 galaxies from millimeter observations D. Schaerer1,2, F. Boone2, M. Zamojski1, J. Staguhn3,4, M. Dessauges-Zavadsky1 , S. Finkelstein5,andF.Combes6 1 Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland e-mail: [email protected] 2 CNRS, IRAP, 14 avenue É. Belin, 31400 Toulouse, France 3 The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, MD 21218, Baltimore, USA 4 Observational Cosmology Lab., Code 665, NASA at Goddard Space Flight Center, MD 20771, Greenbelt, USA 5 The University of Texas at Austin, Austin, TX 78712, USA 6 Observatoire de Paris, LERMA, 61 Av. de l’Observatoire, 75014 Paris, France Received 21 July 2014 / Accepted 3 November 2014 ABSTRACT Context. Determining the dust properties and UV attenuation of distant star-forming galaxies is of great interest for our understanding of galaxy formation and cosmic star formation in the early Universe. However, few direct measurements exist so far. Aims. To shed new light on these questions, we have targeted two recently discovered Lyman-break galaxies (LBGs) at z ≈ 6.8and z = 7.508 to search for dust continuum and [C ii] λ158 μm line emission. Methods. The strongly lensed z ≈ 6.8 LBG A1703-zD1 behind the galaxy cluster Abell 1703 and the spectroscopically confirmed z = 7.508 LBG z8-GND-5296 in the GOODS-N field were observed with the Plateau de Bure Interferometer (PdBI) at 1.2 mm.
    [Show full text]