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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
An Investigation Of The Dust Content In The Galaxy Pair Ngc 1512/1510 From Near-Infrared To Millimeter Wavelengths, Gl Liu, D Calzetti, Min Yun, Gw Wilson, Bt Draine, K Scott, J Austermann, T Perera, D Hughes, I Aretxaga, K Kohno, R Kawabe, H Ezawa
An Investigation Of The Dust Content In The Galaxy Pair Ngc 1512/1510 From Near-Infrared To Millimeter Wavelengths, Gl Liu, D Calzetti, Min Yun, Gw Wilson, Bt Draine, K Scott, J Austermann, T Perera, D Hughes, I Aretxaga, K Kohno, R Kawabe, H Ezawa
Astronomy Department Faculty Publication Series
We combine new ASTE/AzTEC 1.1 mm maps of the galaxy pair NGC 1512/1510 with archival Spitzer IRAC and MIPS images covering the wavelength range 3.6-160 μm from the SINGS project. The availability of the 1.1 mm map enables us to measure the long-wavelength tail of the dust emission in each galaxy, and in sub-galactic regions in NGC 1512, and to derive accurate dust masses. The two galaxies form a pair consisting of a large, high-metallicity spiral (NGC 1512) and a low-metallicity, blue compact dwarf (NGC 1510), which we use to compare similarities and contrast differences. Using the models of Draine …
Dust Emission And Star Formation In Stephan's Quintet, G Natale, Rj Tuffs, Ck Xu, Cc Popescu, J Fischera, U Lisenfeld, N Lu, P Appleton, M Dopita, P-A Duc, W Reach, J Sulentic, Min Yun
Dust Emission And Star Formation In Stephan's Quintet, G Natale, Rj Tuffs, Ck Xu, Cc Popescu, J Fischera, U Lisenfeld, N Lu, P Appleton, M Dopita, P-A Duc, W Reach, J Sulentic, Min Yun
Astronomy Department Faculty Publication Series
We analyze a comprehensive set of MIR/FIR observations of Stephan's Quintet (SQ), taken with the Spitzer Space Telescope. Our study reveals the presence of a luminous (L IR 4.6 × 1043 erg s-1) and extended component of infrared dust emission, not connected with the main bodies of the galaxies, but roughly coincident with the X-ray halo of the group. We fitted the inferred dust emission spectral energy distribution of this extended source and the other main infrared emission components of SQ, including the intergalactic shock, to elucidate the mechanisms powering the dust and polycyclic aromatic …
The Relation Between Gas And Dust In The Taurus Molecular Cloud, G Pineda, P Goldsmith, N Chapman, Ronald L. Snell, D Li, L Cambresy, C Brunt
The Relation Between Gas And Dust In The Taurus Molecular Cloud, G Pineda, P Goldsmith, N Chapman, Ronald L. Snell, D Li, L Cambresy, C Brunt
Astronomy Department Faculty Publication Series
We report a study of the relation between dust and gas over a 100 deg2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J = 1 → 0 lines. We derive the visual extinction from reddening determined from 2MASS data. The comparison is done at an angular size of 200'' corresponding to 0.14 pc at a distance of 140 pc. We find that the relation between visual extinction A V and N(CO) is linear between A …
Dust-Corrected Star Formation Rates Of Galaxies. I. Combinations Of H Alpha And Infrared Tracers, Rc Kennicutt, Cn Hao, D Calzetti, J Moustakas, Da Dale, G Bendo, Cw Engelbracht, Bd Johnson, Jc Lee
Dust-Corrected Star Formation Rates Of Galaxies. I. Combinations Of H Alpha And Infrared Tracers, Rc Kennicutt, Cn Hao, D Calzetti, J Moustakas, Da Dale, G Bendo, Cw Engelbracht, Bd Johnson, Jc Lee
Astronomy Department Faculty Publication Series
We combine Hα emission-line and infrared (IR) continuum measurements of two samples of nearby galaxies to derive dust attenuation-corrected star formation rates (SFRs). We use a simple energy balance based method that has been applied previously to H II regions in the Spitzer Infrared Nearby Galaxies Survey, and extend the methodology to integrated measurements of galaxies. We find that our composite Hα + IR based SFRs are in excellent agreement with attenuation-corrected SFRs derived from integrated spectrophotometry, over the full range of SFRs (0.01-80 M sun yr-1) and attenuations (0-2.5 mag) studied. We find that the combination of Hα and …
The Opacity Of Spiral Galaxy Disks. Viii. Structure Of The Cold Ism, Bw Holwerda, B Draine, Kd Gordon, Ra Gonzalez, D Calzetti, M Thornley, B Buckalew, Rj Allen, Pc Van Der Kruit
The Opacity Of Spiral Galaxy Disks. Viii. Structure Of The Cold Ism, Bw Holwerda, B Draine, Kd Gordon, Ra Gonzalez, D Calzetti, M Thornley, B Buckalew, Rj Allen, Pc Van Der Kruit
Astronomy Department Faculty Publication Series
The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper we compare two techniques, one based on emission and one on absorption, applied to sections of 14 disk galaxies. The two measurements reflect, respectively, the average and apparent optical depth of a disk section. Hence, they depend differently on the average number and optical depth of ISM structures in the disk. The small-scale geometry of the cold ISM is critical for accurate models of the overall energy budget of spiral disks. ISM geometry, relative …
Gaps In The Cloud Cover? Comparing Extinction Measures In Spiral Disks, Bw Holwerda, M Meyer, M Regan, D Calzetti, Kd Gordon, Jd Smith, D Dale, Cw Engelbracht, T Jarrett, M Thornley, C Bot, B Buckalew, Rc Kennicutt, Ra Gonzalez
Gaps In The Cloud Cover? Comparing Extinction Measures In Spiral Disks, Bw Holwerda, M Meyer, M Regan, D Calzetti, Kd Gordon, Jd Smith, D Dale, Cw Engelbracht, T Jarrett, M Thornley, C Bot, B Buckalew, Rc Kennicutt, Ra Gonzalez
Astronomy Department Faculty Publication Series
Dust in galaxies can be mapped either by the FIR/submillimeter emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of 15 sections in 13 nearby galaxies to determine the scale of the dusty interstellar medium (ISM) responsible for disk opacity: one using stellar reddening and the other a known background source. In our earlier papers, we presented extinction measurements of 29 galaxies, based on calibrated counts of distant background objects identified though foreground disks in Hubble Space Telescope WFPC2 images. For the 13 galaxies …
The Canada-Uk Deep Submillimetre Survey - Viii. Source Identifications In The 3-Hour Field, D Clements, S Eales, K Wojciechowski, T Webb, S Lilly, L Dunne, R Ivison, H Mccracken, Min Yun, A James, M Brodwin, O Le Fevre, W Gear
The Canada-Uk Deep Submillimetre Survey - Viii. Source Identifications In The 3-Hour Field, D Clements, S Eales, K Wojciechowski, T Webb, S Lilly, L Dunne, R Ivison, H Mccracken, Min Yun, A James, M Brodwin, O Le Fevre, W Gear
Astronomy Department Faculty Publication Series
We present optical, near-infrared (IR) and radio observations of the 3-hour field of the Canada–UK Deep Submillimetre Survey (CUDSS). Of the 27 submillimetre sources in the field, nine have secure identifications with either a radio source or a near-IR source. We show that the percentage of sources with secure identifications in the CUDSS is consistent with that found for the bright ‘8-mJy’ submillimetre survey, once allowance is made for the different submillimetre and radio flux limits. Of the 14 secure identifications in the two CUDSS fields, eight are very red objects (VROs) or extremely red objects (EROs), five have colours …
Enrichment Of The Intergalactic Medium By Radiation Pressure-Driven Dust Efflux, A Aguirre, L Hernquist, N Katz, J Gardner, D Weinberg
Enrichment Of The Intergalactic Medium By Radiation Pressure-Driven Dust Efflux, A Aguirre, L Hernquist, N Katz, J Gardner, D Weinberg
Astronomy Department Faculty Publication Series
The presence of metals in hot cluster gas and in Lyα absorbers, as well as the mass-metallicity relation of observed galaxies, suggest that galaxies lose a significant fraction of their metals to the intergalactic medium (IGM). Theoretical studies of this process have concentrated on metal removal by dynamical processes or supernova-driven winds. Here we investigate the enrichment of the IGM by the expulsion of dust grains from galaxies by radiation pressure. We use already completed cosmological simulations to which we add dust, assuming that most dust can reach the equilibrium point between radiation pressure and gravitational forces. We find that …
Simulating The Effects Of Intergalactic Gray Dust, Rac Croft, R Dave, L Hernquist, N Katz
Simulating The Effects Of Intergalactic Gray Dust, Rac Croft, R Dave, L Hernquist, N Katz
Astronomy Department Faculty Publication Series
Using a high-resolution cosmological hydrodynamic simulation, we present a method to constrain extinction due to intergalactic gray dust based on the observed magnitudes of distant Type Ia supernovae. We apply several simple prescriptions to relate the intergalactic dust density to the gas density in the simulation, thereby obtaining dust extinctions that may be directly compared with the observed distribution of supernova magnitudes. Our analysis is sensitive to the spatial distribution of gray dust but is not dependent on its intrinsic properties, such as its opacity or grain size. We present an application of our technique to the supernova data of …