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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Resolving The Far-Ir Line Deficit: Photoelectric Heating And Far-Ir Line Cooling In Ngc 1097 And Ngc 4559, Kevin V. Croxall, J. D. Smith, M. G. Wolfire, H. Roussel, K. M. Sandstrom, B. T. Draine, G. Aniano, D. A. Dale, L. Armus, P. Beirão, G. Helou, A. D. Bolatto, P. N. Appleton, B. R. Brandl, Daniela Calzetti, A. F. Crocker, M. Galametz, B. A. Groves, C.-N. Hao, L. K. Hunt, B. D. Johnson, R, C, Kennicutt, J. Koda, O. Krause, Y. Li, S. E. Meidt, E. J. Murphy, N. Rahman, H.-W. Rix, M. Sauvage, E. Schinnerer, F. Walter, C. D. Wilson
Resolving The Far-Ir Line Deficit: Photoelectric Heating And Far-Ir Line Cooling In Ngc 1097 And Ngc 4559, Kevin V. Croxall, J. D. Smith, M. G. Wolfire, H. Roussel, K. M. Sandstrom, B. T. Draine, G. Aniano, D. A. Dale, L. Armus, P. Beirão, G. Helou, A. D. Bolatto, P. N. Appleton, B. R. Brandl, Daniela Calzetti, A. F. Crocker, M. Galametz, B. A. Groves, C.-N. Hao, L. K. Hunt, B. D. Johnson, R, C, Kennicutt, J. Koda, O. Krause, Y. Li, S. E. Meidt, E. J. Murphy, N. Rahman, H.-W. Rix, M. Sauvage, E. Schinnerer, F. Walter, C. D. Wilson
Daniela Calzetti
The physical state of interstellar gas and dust is dependent on the processes which heat and cool this medium. To probe heating and cooling of the ISM over a large range of infrared surface brightness, on sub-kiloparsec scales, we employ line maps of [C \ii] 158 $\mu$m, [O \one] 63 $\mu$m, and [N \ii] 122 $\mu$m in NGC 1097 and NGC 4559, obtained with the PACS spectrometer onboard {\it Herschel}. We matched new observations to existing Spitzer-IRS data that trace the total emission of polycyclic aromatic hydrocarbons (PAHs). We confirm at small scales in these galaxies that the canonical measure …
Cool And Warm Dust Emission From M33 (Herm33es), E. M. Xilouris, F. S. Tabatabaei, M. Boquien, C. Kramer, C. Buchbender, F. Bertoldi, S. Anderl, J. Braine, S. Verley, M. Relaño, G. Quintana-Lacaci, S. Akras, R. Beck, Daniela Calzetti, F. Combes, M. Gonzalez, P. Gratier, C. Henkel, F. Israel, B. Koribalski, S. Lord, B. Mookerjea, E. Rosolowsky, G. Stacey, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf
Cool And Warm Dust Emission From M33 (Herm33es), E. M. Xilouris, F. S. Tabatabaei, M. Boquien, C. Kramer, C. Buchbender, F. Bertoldi, S. Anderl, J. Braine, S. Verley, M. Relaño, G. Quintana-Lacaci, S. Akras, R. Beck, Daniela Calzetti, F. Combes, M. Gonzalez, P. Gratier, C. Henkel, F. Israel, B. Koribalski, S. Lord, B. Mookerjea, E. Rosolowsky, G. Stacey, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf
Daniela Calzetti
We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength coverage (100, 160, 250, 350 and 500 micron) of the Herschel Space Observatory and complementing our dataset with Spitzer-IRAC 5.8 and 8 micron and Spitzer-MIPS 24 and 70 micron data, we construct temperature and luminosity density maps by fitting two modified blackbodies of a fixed emissivity index of 1.5. We find that the 'cool' dust grains are heated at temperatures between 11 and 28 …
Dust And Gas Power-Spectrum In M33 (Herm33es), F. Combes, M. Boquien, C. Kramer, E. M. Xilouris, F. Bertoldi, J. Braine, C. Buchbender, Daniela Calzetti, P. Gratier, F. Israel, B. Koribalski, S. Lord, G. Quintana-Lacaci, M. Relaño, M. Röllig, G. Stacey, F. S. Tabatabaei, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf, S. Verley
Dust And Gas Power-Spectrum In M33 (Herm33es), F. Combes, M. Boquien, C. Kramer, E. M. Xilouris, F. Bertoldi, J. Braine, C. Buchbender, Daniela Calzetti, P. Gratier, F. Israel, B. Koribalski, S. Lord, G. Quintana-Lacaci, M. Relaño, M. Röllig, G. Stacey, F. S. Tabatabaei, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf, S. Verley
Daniela Calzetti
Power spectra of de-projected images of late-type galaxies in gas and/or dust emission are very useful diagnostics of the dynamics and stability of their interstellar medium. Previous studies have shown that the power spectra can be approximated as two power-laws, a shallow one at large scales (larger than 500 pc) and a steeper one at small scales, with the break between the two corresponding to the line-of-sight thickness of the galaxy disk. We present a thorough analysis of the power spectra of the dust and gas emission at several wavelengths in the nearby galaxy M33. In particular, we use the …
A Study Of Heating And Cooling Of The Ism In Ngc 1097 With Herschel-Pacs And Spitzer-Irs, P. Beirão, L. Armus, G. Helou, P. N. Appleton, J.-D. T. Smith, K. V. Croxall, E. J. Murphy, D. A. Dale, B. T. Draine, M. G. Wolfire, K. M. Sandstrom, G. Aniano, A. D. Bolatto, B. Groves, B. R. Brandl, E. Schinnerer, A. F. Crocker, J. L. Hinz, H.-W. Rix, R. C. Kennicutt, Daniela Calzetti, A. Gil De Paz, G. Dumas, M. Galametz, K. D. Gordon, C.-N. Hao, B. Johnson, J. Koda, O. Krause, T. Van Der Laan, A. K. Leroy, Y. Li, S. E. Meidt, J. D. Meyer, N. Rahman, H. Roussel, M. Sauvage, S. Srinivasan, L. Vigroux, F. Walter, B. E. Warren
A Study Of Heating And Cooling Of The Ism In Ngc 1097 With Herschel-Pacs And Spitzer-Irs, P. Beirão, L. Armus, G. Helou, P. N. Appleton, J.-D. T. Smith, K. V. Croxall, E. J. Murphy, D. A. Dale, B. T. Draine, M. G. Wolfire, K. M. Sandstrom, G. Aniano, A. D. Bolatto, B. Groves, B. R. Brandl, E. Schinnerer, A. F. Crocker, J. L. Hinz, H.-W. Rix, R. C. Kennicutt, Daniela Calzetti, A. Gil De Paz, G. Dumas, M. Galametz, K. D. Gordon, C.-N. Hao, B. Johnson, J. Koda, O. Krause, T. Van Der Laan, A. K. Leroy, Y. Li, S. E. Meidt, J. D. Meyer, N. Rahman, H. Roussel, M. Sauvage, S. Srinivasan, L. Vigroux, F. Walter, B. E. Warren
Daniela Calzetti
NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar and an active nucleus. We present a detailed study of the spatial variation of the far infrared (FIR) [CII]158um and [OI]63um lines and mid-infrared H2 emission lines as tracers of gas cooling, and of the polycyclic aromatic hydrocarbon (PAH) bands as tracers of the photoelectric heating, using Herschel-PACS, and Spitzer-IRS infrared spectral maps. We focus on the nucleus and the ring, and two star forming regions (Enuc N and Enuc S). We estimated a photoelectric gas heating efficiency ([CII]158um+[OI]63um)/PAH in the ring …
A Panchromatic Catalog Of Early-Type Galaxies At Intermediate Redshift In The Hubble Space Telescope Wide Field Camera 3 Early Release Science Field, M. J. Rutkowski, S. H. Cohen, S. Kaviraj, R. W. O'Connell, N. P. Hathi, R. A. Windhorst, R. E. Ryan Jr., R. M. Crockett, H. Yan, R. A. Kimble, J. Silk, P.J. Mccarthy, A. Koekemoer, B. Balick, H. E. Bond, Daniela Calzetti, M. J. Disney, M. A. Dopita, J. A. Frogel, D. N. B. Hall, J. A. Holtzman, F. Paresce, A. Saha, J. T. Trauger, A. R. Walker, B. C. Whitmore, E. T. Young
A Panchromatic Catalog Of Early-Type Galaxies At Intermediate Redshift In The Hubble Space Telescope Wide Field Camera 3 Early Release Science Field, M. J. Rutkowski, S. H. Cohen, S. Kaviraj, R. W. O'Connell, N. P. Hathi, R. A. Windhorst, R. E. Ryan Jr., R. M. Crockett, H. Yan, R. A. Kimble, J. Silk, P.J. Mccarthy, A. Koekemoer, B. Balick, H. E. Bond, Daniela Calzetti, M. J. Disney, M. A. Dopita, J. A. Frogel, D. N. B. Hall, J. A. Holtzman, F. Paresce, A. Saha, J. T. Trauger, A. R. Walker, B. C. Whitmore, E. T. Young
Daniela Calzetti
In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually-selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 < z < 1.5, with each redshift spectroscopically-confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and ACS GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broad-band photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 11< log(M [Solar]) < 12. By transforming the observed photometry into the GALEX FUV and NUV, Johnson V, and SDSS g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V)=3.5 and (NUV-V)=3.3, with 1$\sigma$ standard deviations approximately equal to 1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star-formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent (<~50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star-formation episodes are activated, are discussed.
Direct Oxygen Abundances For Low Luminosity Lvl Galaxies, Danielle A. Berg, Evan D. Skillman, Andrew R. Marble, Liese Van Zee, Charles W. Engelbracht, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Daniel A. Dale, Benjamin D. Johnson
Direct Oxygen Abundances For Low Luminosity Lvl Galaxies, Danielle A. Berg, Evan D. Skillman, Andrew R. Marble, Liese Van Zee, Charles W. Engelbracht, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Daniel A. Dale, Benjamin D. Johnson
Daniela Calzetti
We present MMT spectroscopic observations of HII regions in 42 low luminosity galaxies in the LVL. For 31 galaxies, we measured the temperature sensitive [O III] line at a strength of 4 sigma or greater, and thus determine direct oxygen abundances. Our results provide the first direct estimates of oxygen abundance for 19 galaxies. Oxygen abundances were compared to B-band and 4.5 micron luminosities and stellar masses in order to characterize the luminosity-metallicity (L-Z) and mass-metallicity (M-Z) relationships at low-luminosity. We present and analyze a "Combined Select" sample composed of 38 objects (drawn from our parent sample and the literature) …
Star Formation Laws: The Effects Of Gas Cloud Sampling, Daniela Calzetti, G. Liu, J. Koda
Star Formation Laws: The Effects Of Gas Cloud Sampling, Daniela Calzetti, G. Liu, J. Koda
Daniela Calzetti
Recent observational results indicate that the functional shape of the spatially-resolved star formation-molecular gas density relation depends on the spatial scale considered. These results may indicate a fundamental role of sampling effects on scales that are typically only a few times larger than those of the largest molecular clouds. To investigate the impact of this effect, we construct simple models for the distribution of molecular clouds in a typical star-forming spiral galaxy, and, assuming a power-law relation between SFR and cloud mass, explore a range of input parameters. We confirm that the slope and the scatter of the simulated SFR-molecular …