Predicting Quiescence: The Dependence of Specific Star Formation Rate on Galaxy Size and Central Density at 0.5 < z < 2.5
AuthorWhitaker, Katherine E.
van Dokkum, Pieter G.
van der Wel, Arjen
Brammer, Gabriel B.
Schreiber, Natascha M. Förster
Momcheva, Ivelina G.
Nelson, Erica J.
Skelton, Rosalind E.
AffiliationUniv Arizona, Steward Observ, Dept Astron
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationPredicting Quiescence: The Dependence of Specific Star Formation Rate on Galaxy Size and Central Density at 0.5 < z < 2.5 2017, 838 (1):19 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2017. The American Astronomical Society. All rights reserved.
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.
AbstractIn this paper, we investigate the relationship between star formation and structure, using a mass-complete sample of 27,893 galaxies at 0.5. <. z. <. 2.5 selected from 3D-HST. We confirm that star-forming galaxies are larger than quiescent galaxies at fixed stellar mass (M*). However, in contrast with some simulations, there is only a weak relation between star formation rate (SFR) and size within the star-forming population: when dividing into quartiles based on residual offsets in SFR, we find that the sizes of star-forming galaxies in the lowest quartile are 0.27. +/-. 0.06 dex smaller than the highest quartile. We show that 50% of star formation in galaxies at fixed M. takes place within a narrow range of sizes (0.26 dex). Taken together, these results suggest that there is an abrupt cessation of star formation after galaxies attain particular structural properties. Confirming earlier results, we find that central stellar density within a 1 kpc fixed physical radius is the key parameter connecting galaxy morphology and star formation histories: galaxies with high central densities are red and have increasingly lower SFR/M., whereas galaxies with low central densities are blue and have a roughly constant (higher) SFR/M. at a given redshift. We find remarkably little scatter in the average trends and a strong evolution of > 0.5 dex in the central density threshold correlated with quiescence from z.similar to. 0.7-2.0. Neither a compact size nor high-n are sufficient to assess the likelihood of quiescence for the average galaxy; instead, the combination of these two parameters together with M* results in a unique quenching threshold in central density/velocity.
VersionFinal published version
SponsorsNASA through Hubble Fellowship - Space Telescope Science Institute [HST-HF2-51368]; NASA [NAS 5-26555, NAS5-26555]; 3D-HST Treasury Program [GO 12177, 12328]; NASA/ ESA HST
Showing items related by title, author, creator and subject.
The MOSDEF Survey: The Nature of Mid-infrared Excess Galaxies and a Comparison of IR and UV Star Formation Tracers at z ∼ 2Azadi, Mojegan; Coil, Alison; Aird, James; Shivaei, Irene; Reddy, Naveen; Shapley, Alice; Kriek, Mariska; Freeman, William R.; Leung, Gene C. K.; Mobasher, Bahram; et al. (IOP PUBLISHING LTD, 2018-10-10)We present an analysis using the MOSFIRE Deep Evolution Field (MOSDEF) survey on the nature of "MIR-excess" galaxies, which have star formation rates (SFRs) inferred from mid-infrared (MIR) data that are substantially elevated relative to those estimated from dust-corrected UV data. We use a sample of similar to 200 galaxies and active galactic nuclei (AGNs) at 1.40 < z < 2.61 with 24 mu m detections (rest-frame 8 mu m) from MIPS/Spitzer. We find that the identification of MIR-excess galaxies strongly depends on the methodologies used to estimate IR luminosity (L-IR) and to correct the UV light for dust attenuation. We find that extrapolations of the SFR from the observed 24 mu m flux, using luminosity-dependent templates based on local galaxies, substantially overestimate L-IR in z similar to 2 galaxies. By including Herschel observations and using a stellar-mass-dependent, luminosity-independent L-IR, we obtain more reliable estimates of the SFR and a lower fraction of MIR-excess galaxies. Once stellar-mass selection biases are taken into account, we identify similar to 24% of our galaxies as MIR excess. However, SFRH alpha is not elevated in MIR-excess galaxies compared to MIR-normal galaxies, indicating that the intrinsic fraction of MIR excess may be lower. Using X-ray-, IR-, and optically selected AGNs in MOSDEF, we do not find a higher prevalence for AGNs in MIR-excess galaxies relative to MIR-normal galaxies. A stacking analysis of X-ray-undetected galaxies does not reveal a harder spectrum in MIR-excess galaxies relative to MIR-normal galaxies. Our analysis indicates that AGN activity does not contribute substantially to the MIR excess and instead implies that it is likely due to the enhanced polycyclic aromatic hydrocarbon emission.
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)Majewski, Steven R.; Schiavon, Ricardo P.; Frinchaboy, P. M.; Prieto, Carlos Allende; Barkhouser, Robert; Bizyaev, Dmitry; Blank, Basil; Brunner, Sophia; Burton, Adam; Carrera, R.; et al. (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.
Exploring the dust content of galactic winds with Herschel – II. Nearby dwarf galaxiesMcCormick, Alexander; Veilleux, Sylvain; Meléndez, Marcio; Martin, Crystal L; Bland-Hawthorn, Joss; Cecil, Gerald; Heitsch, Fabian; Müller, Thomas; Rupke, David S N; Engelbracht, Chad; et al. (OXFORD UNIV PRESS, 2018-06)We present the results from an analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 mu m images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically similar to 10-20 per cent of the total dust mass in these galaxies resides outside of their stellar discs, but this fraction reaches similar to 60 per cent in the case of NGC 1569. This galaxy also has the largest metal-licity (O/H) deficit in our sample for its stellar mass. Overall, the small number of objects in our sample precludes drawing strong conclusions on the origin of the circumgalactic dust. We detect no statistically significant trends with star formation properties of the host galaxies, as might be expected if the dust were lifted above the disc by energy inputs from ongoing star formation activity. Although a case for dust entrained in a galactic wind is seen in NGC 1569, in all cases, we cannot rule out the possibility that some of the circumgalactic dust might be associated instead with gas accreted or removed from the disc by recent galaxy interaction events, or that it is part of the outer gas-rich portion of the disc that lies below the sensitivity limit of the Spitzer 4.5 mu m data.