Le Floc’h, E.
AffiliationUniv Arizona, Steward Observ
galaxies: star formation
MetadataShow full item record
PublisherEDP SCIENCES S A
CitationPlanck’s dusty GEMS 2017, 604:A117 Astronomy & Astrophysics
JournalAstronomy & Astrophysics
Rights© ESO, 2017
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractWe present an analysis of high-resolution ALMA interferometry of CO(4-3) line emission and dust continuum in the "Ruby" (PLCK_G244.8+54.9), a bright, gravitationally lensed galaxy at z = 3.0 discovered with the Planck all-sky survey. The Ruby is the brightest of Planck's dusty GEMS, a sample of 11 of the brightest gravitationally lensed high-redshift galaxies on the extragalactic sub-mm sky. We resolve the high-surface-brightness continuum and CO line emission of the Ruby in several extended clumps along a partial, nearly circular Einstein ring with 1.4 '' diameter around a massive galaxy at z = 1.5. Local star-formation intensities are up to 2000 M-circle dot yr(-1) kpc(-2), amongst the highest observed at high redshift, and clearly in the range of maximal starbursts. Gas-mass surface densities are a few x10(4) M-circle dot pc(-2). The Ruby lies at, and in part even above, the starburst sequence in the Schmidt-Kennicutt diagram, and at the limit expected for star formation that is self-regulated through the kinetic energy injection from radiation pressure, stellar winds, and supernovae. We show that these processes can also inject sufficient kinetic energy and momentum into the gas to explain the turbulent line widths, which are consistent with marginally gravitationally bound molecular clouds embedded in a critically Toomre-stable disk. The star-formation efficiency is in the range 1-10% per free-fall time, consistent with the notion that the pressure balance that sets the local star-formation law in the Milky Way may well be universal out to the highest star-formation intensities. AGN feedback is not necessary to regulate the star formation in the Ruby, in agreement with the absence of a bright AGN component in the infrared and radio regimes.
NoteOpen access journal.
VersionFinal published version
SponsorsJAO visitor grant; CNRS; CNES; European Research Council in the form of the Advanced Investigator Programme [321302, COSMICISM]
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Was 49b: An Overmassive AGN in a Merging Dwarf Galaxy?Secrest, Nathan J.; Schmitt, Henrique R.; Blecha, Laura; Rothberg, Barry; Fischer, Jacqueline; Univ Arizona, LBT Observ (IOP PUBLISHING LTD, 2017-02-17)We present a combined morphological and X-ray analysis of Was. 49, an isolated, dual-AGN system notable for the presence of a dominant AGN, Was 49b, in the disk of the primary galaxy, Was 49a, at a projected radial distance of 8. kpc from the nucleus. Using X-ray data from Chandra, the Nuclear Spectroscopic Telescope Array, and Swift, we find that this AGN has a bolometric luminosity of L-bol similar to 10(45) erg s(-1), with a black hole mass of M-BH = 1.3(-0.9)(+10)M(circle dot) . Despite the large mass, our analysis of optical data from the Discovery Channel Telescope shows that the supermassive black hole (SMBH) is hosted by a stellar counterpart with a mass of only 5.6(-2.6)(+4.9)M(circle dot), which makes the SMBH potentially larger than expected from SMBH-galaxy scaling relations, and the stellar counterpart exhibits a morphology that is consistent with dwarf elliptical galaxies. Our analysis of the system in the r and K bands indicates that Was. 49 is a minor merger, with the mass ratio of Was 49b to Was 49a between similar to 1:7 and similar to 1:15. This is in contrast with findings that the most luminous merger-triggered AGNs are found in major mergers and that minor mergers predominantly enhance AGN activity in the primary galaxy.
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)Majewski, Steven R.; Schiavon, Ricardo P.; Frinchaboy, Peter M.; Prieto, Carlos Allende; Barkhouser, Robert; Bizyaev, Dmitry; Blank, Basil; Brunner, Sophia; Burton, Adam; Carrera, Ricardo; Chojnowski, S. Drew; Cunha, Kátia; Epstein, Courtney; Fitzgerald, Greg; Pérez, Ana E. García; Hearty, Fred R.; Henderson, Chuck; Holtzman, Jon A.; Johnson, Jennifer A.; Lam, Charles R.; Lawler, James E.; Maseman, Paul; Mészáros, Szabolcs; Nelson, Matthew; Nguyen, Duy Coung; Nidever, David L.; Pinsonneault, Marc; Shetrone, Matthew; Smee, Stephen; Smith, Verne V.; Stolberg, Todd; Skrutskie, Michael F.; Walker, Eric; Wilson, John C.; Zasowski, Gail; Anders, Friedrich; Basu, Sarbani; Beland, Stephane; Blanton, Michael R.; Bovy, Jo; Brownstein, Joel R.; Carlberg, Joleen; Chaplin, William; Chiappini, Cristina; Eisenstein, Daniel J.; Elsworth, Yvonne; Feuillet, Diane; Fleming, Scott W.; Galbraith-Frew, Jessica; García, Rafael A.; García-Hernández, D. Aníbal; Gillespie, Bruce A.; Girardi, Léo; Gunn, James E.; Hasselquist, Sten; Hayden, Michael R.; Hekker, Saskia; Ivans, Inese; Kinemuchi, Karen; Klaene, Mark; Mahadevan, Suvrath; Mathur, Savita; Mosser, Benoît; Muna, Demitri; Munn, Jeffrey A.; Nichol, Robert C.; O’Connell, Robert W.; Parejko, John K.; Robin, A. C.; Rocha-Pinto, Helio; Schultheis, Matthias; Serenelli, Aldo M.; Shane, Neville; Aguirre, Victor Silva; Sobeck, Jennifer S.; Thompson, Benjamin; Troup, Nicholas W.; Weinberg, David H.; Zamora, Olga; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2017-08-14)The Apache Point Observatory Galactic Evolution Experiment (APOGEE), one of the programs in the Sloan Digital Sky Survey III (SDSS-III), has now completed its systematic, homogeneous spectroscopic survey sampling all major populations of the Milky Way. After a three-year observing campaign on the Sloan 2.5 m Telescope, APOGEE has collected a half million high-resolution (R similar to 22,500), high signal-to-noise ratio (>100), infrared (1.51-1.70 mu m) spectra for 146,000 stars, with time series information via repeat visits to most of these stars. This paper describes the motivations for the survey and its overall design-hardware, field placement, target selection, operations-and gives an overview of these aspects as well as the data reduction, analysis, and products. An index is also given to the complement of technical papers that describe various critical survey components in detail. Finally, we discuss the achieved survey performance and illustrate the variety of potential uses of the data products by way of a number of science demonstrations, which span from time series analysis of stellar spectral variations and radial velocity variations from stellar companions, to spatial maps of kinematics, metallicity, and abundance patterns across the Galaxy and as a function of age, to new views of the interstellar medium, the chemistry of star clusters, and the discovery of rare stellar species. As part of SDSS-III Data Release 12 and later releases, all of the APOGEE data products are publicly available.
STELLAR MASS–GAS-PHASE METALLICITY RELATION AT 0.5 ≤ z ≤ 0.7: A POWER LAW WITH INCREASING SCATTER TOWARD THE LOW-MASS REGIMEGuo, Yicheng; Koo, David C.; Lu, Yu; Forbes, John C.; Rafelski, Marc; Trump, Jonathan R.; Amorín, Ricardo; Barro, Guillermo; Davé, Romeel; Faber, S. M.; Hathi, Nimish P.; Yesuf, Hassen; Cooper, Michael C.; Dekel, Avishai; Guhathakurta, Puragra; Kirby, Evan N.; Koekemoer, Anton M.; Pérez-González, Pablo G.; Lin, Lihwai; Newman, Jeffery A.; Primack, Joel R.; Rosario, David J.; Willmer, Christopher N. A.; Yan, Renbin; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2016-05-11)We present the stellar mass (M-*)-gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5 <= z <= 0.7) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given M-* of this magnitude-limited (R less than or similar to 24 AB) sample are representative of normal star-forming galaxies. For masses below 10(9) M-circle dot, our sample of 237 galaxies is similar to 10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and its scatter in the low-mass regime. We find a power-law MZR at 10(8) M-circle dot < M-* < 10(11) M-circle dot: 12 + log (O/H) = (5.83 +/- 0.19)+(0.30 +/- 0.02) log (M-*/M-circle dot). At 10(9) M-circle dot < M-* < 10(10.5) M-circle dot, our MZR shows agreement with others measured at similar redshifts in the literature. Our power-law slope is, however, shallower than the extrapolation of the MZRs of others to masses below 10(9) M-circle dot. The SFR dependence of the MZR in our sample is weaker than that found for local galaxies (known as the fundamental metallicity relation). Compared to a variety of theoretical models, the slope of our MZR for low-mass galaxies agrees well with predictions incorporating supernova energy-driven winds. Being robust against currently uncertain metallicity calibrations, the scatter of the MZR serves as a powerful diagnostic of the stochastic history of gas accretion, gas recycling, and star formation of low-mass galaxies. Our major result is that the scatter of our MZR increases as M-* decreases. Our result implies that either the scatter of the baryonic accretion rate (sigma((M) over dot)) or the scatter of the M-*-M-halo relation (sigma(SHMR)) increases as M-* decreases. Moreover, our measure of scatter at z = 0.7 appears consistent with that found for local galaxies. This lack of redshift evolution constrains models of galaxy evolution to have both sigma((M) over dot) and sigma(SHMR) remain unchanged from z = 0.7 to z = 0.