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Your search keyword '"Gouliermis, DA [0000-0002-2763-0075]"' showing total 2 results
Start Over Author "Gouliermis, DA [0000-0002-2763-0075]" Topic astrophysics - astrophysics of galaxies
2 results on '"Gouliermis, DA [0000-0002-2763-0075]"'

1. A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions

Author

Stacey N. Bright, Robert C. Kennicutt, Angela Adamo, David O. Cook, Deidre A. Hunter, Bruce G. Elmegreen, Michele Fumagalli, Elena Sabbi, Matteo Messa, Lauren Kahre, J. E. Ryon, Elena Sacchi, L. Ubeda, John S. Gallagher, Se-Heon Oh, Hong-Xin Zhang, Eva K. Grebel, Monica Tosi, Daniel A. Dale, Hwihyun Kim, Kathryn Grasha, Dimitrios A. Gouliermis, Samavarti Gallardo, Michele Cignoni, Daniela Calzetti, Janice C. Lee, Hunter, D, Gallardo, S, Zhang, H, Adamo, A, Cook, D, Oh, S, Elmegreen, B, Kim, H, Kahre, L, Ubeda, L, Bright, S, Ryon, J, Fumagalli, M, Sacchi, E, Kennicutt, R, Tosi, M, Dale, D, Cignoni, M, Messa, M, Grebel, E, Gouliermis, D, Sabbi, E, Grasha, K, Gallagher, J, Calzetti, D, Lee, J, Hunter, DA [0000-0002-3322-9798], Adamo, A [0000-0002-8192-8091], Cook, DO [0000-0002-6877-7655], Oh, SH [0000-0002-5648-9920], Elmegreen, BG [0000-0002-1723-6330], Kim, H [0000-0003-4770-688X], Kahre, L [0000-0002-2037-3096], Fumagalli, M [0000-0001-6676-3842], Sacchi, E [0000-0001-5618-0109], Tosi, M [0000-0002-0986-4759], Dale, DA [0000-0002-5782-9093], Cignoni, M [0000-0001-6291-6813], Grebel, EK [0000-0002-1891-3794], Gouliermis, DA [0000-0002-2763-0075], Sabbi, E [0000-0003-2954-7643], Grasha, K [0000-0002-3247-5321], Gallagher, JS [0000-0001-8608-0408], Calzetti, D [0000-0002-5189-8004], Lee, JC [0000-0002-2278-9407], and Apollo - University of Cambridge Repository

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, galaxies: individual (DDO 187, NGC 3738), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Rotation, 01 natural sciences, 0103 physical sciences, Dispersion (optics), Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, NGC 3738), Star formation, Astronomy and Astrophysics, galaxies: dwarf, galaxies: individual (DDO 187, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, Irregular galaxy
Abstract

Two dwarf irregular galaxies DDO 187 and NGC 3738 exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the HI distribution and kinematics and stellar images and colors to examine the properties of the environment in the high star formation rate (HSF) halves of the galaxies in comparison with the low star formation rate (LSF) halves. We find that the pressure and gas density are higher on the HSF sides by 30-70%. In addition we find in both galaxies that the HI velocity fields exhibit significant deviations from ordered rotation and there are large regions of high velocity dispersion and multiple velocity components in the gas beyond the inner regions of the galaxies. The conditions in the HSF regions are likely the result of large-scale external processes affecting the internal environment of the galaxies and enabling the current star formation there., Comment: In press in ApJ

Published
2018
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2. Extinction Maps and Dust-to-gas Ratios in Nearby Galaxies with LEGUS

Author

Leonardo Ubeda, Aaron S. Evans, Debra Meloy Elmegreen, Brad Whitmore, Daniel A. Dale, Janice C. Lee, Rene A. M. Walterbos, Carol Christian, Linda J. Smith, Rupali Chandar, Hwihyun Kim, R. C. Kennicutt, F. Shabani, Kathryn Grasha, Clare Dobbs, Dimitrios A. Gouliermis, Jennifer E. Andrews, Bruce G. Elmegreen, Alessandra Aloisi, Daniela Calzetti, J. E. Ryon, Michele Cignoni, Aida Wofford, Deidre A. Hunter, Michele Fumagalli, S. E. de Mink, John S. Gallagher, Elena Sabbi, David A. Thilker, Stacey N. Bright, Daniel Schaerer, S. D. Van Dyk, Preethi Nair, Kelsey E. Johnson, Matteo Messa, Antonella Nota, A. Herrero, Mark R. Krumholz, Elena Sacchi, Thomas M. Brown, Angela Adamo, L. Kahre, G. Ashworth, Eva K. Grebel, Monica Tosi, David O. Cook, Anne Pellerin, Low Energy Astrophysics (API, FNWI), Kahre, L [0000-0002-2037-3096], Walterbos, RA [0000-0002-0782-3064], Kim, H [0000-0003-4770-688X], Thilker, D [0000-0002-8528-7340], Calzetti, D [0000-0002-5189-8004], Lee, JC [0000-0002-2278-9407], Sabbi, E [0000-0003-2954-7643], Aloisi, A [0000-0003-4137-882X], Cignoni, M [0000-0001-6291-6813], Cook, DO [0000-0002-6877-7655], Dale, DA [0000-0002-5782-9093], Elmegreen, BG [0000-0002-1723-6330], Elmegreen, DM [0000-0002-1392-3520], Fumagalli, M [0000-0001-6676-3842], Gallagher, JS [0000-0001-8608-0408], Gouliermis, DA [0000-0002-2763-0075], Grasha, K [0000-0002-3247-5321], Grebel, EK [0000-0002-1891-3794], Hunter, DA [0000-0002-3322-9798], Sacchi, E [0000-0001-5618-0109], Smith, LJ [0000-0002-0806-168X], Tosi, M [0000-0002-0986-4759], Adamo, A [0000-0002-8192-8091], Brown, TM [0000-0002-1793-9968], Chandar, R [0000-0003-0085-4623], Christian, C [0000-0002-2179-3308], De Mink, SE [0000-0001-9336-2825], Herrero, A [0000-0001-8768-2179], Johnson, KE [0000-0001-8348-2671], Krumholz, MR [0000-0003-3893-854X], Pellerin, A [0000-0003-1887-1966], Schaerer, D [0000-0001-7144-7182], Shabani, F [0000-0002-5266-1260], Van Dyk, SD [0000-0001-9038-9950], Apollo - University of Cambridge Repository, Kahre, L, Walterbos, R, Kim, H, Thilker, D, Calzetti, D, Lee, J, Sabbi, E, Ubeda, L, Aloisi, A, Cignoni, M, Cook, D, Dale, D, Elmegreen, B, Elmegreen, D, Fumagalli, M, Gallagher, J, Gouliermis, D, Grasha, K, Grebel, E, Hunter, D, Sacchi, E, Smith, L, Tosi, M, Adamo, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, De Mink, S, Dobbs, C, Evans, A, Herrero, A, Johnson, K, Kennicutt, R, Krumholz, M, Messa, M, Nair, P, Nota, A, Pellerin, A, Ryon, J, Schaerer, D, Shabani, F, Van Dyk, S, Whitmore, B, and Wofford, A

Subjects
galaxies: spiral, Metallicity, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Power law, Hubble space telescope, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ISM: general, Physics, Extinction, 010308 nuclear & particles physics, extinction, Astronomy and Astrophysics, HERA, galaxies: dwarf, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, dust, galaxies: ISM, galaxies: photometry, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Spectral energy distribution, dust, extinction, Astrophysics::Earth and Planetary Astrophysics
Abstract

We present a study of the dust-to-gas ratios in five nearby galaxies NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broad band WFC3/UVIS UV and optical images from the Treasury program LEGUS (Legacy ExtraGalactic UV Survey) combined with archival HST/ACS data, we correct thousands of individual stars for extinction across these five galaxies using an isochrone-matching (reddening-free Q) method. We generate extinction maps for each galaxy from the individual stellar extinctions using both adaptive and fixed resolution techniques, and correlate these maps with neutral HI and CO gas maps from literature, including The HI Nearby Galaxy Survey (THINGS) and the HERA CO-Line Extragalactic Survey (HERACLES). We calculate dust-to-gas ratios and investigate variations in the dust-to-gas ratio with galaxy metallicity. We find a power law relationship between dust-to-gas ratio and metallicity, consistent with other studies of dust-to-gas ratio compared to metallicity. We find a change in the relation when H$_2$ is not included. This implies that underestimation of $N_{H_2}$ in low-metallicity dwarfs from a too-low CO-to-H$_2$ conversion factor $X_{CO}$ could have produced too low a slope in the derived relationship between dust-to-gas ratio and metallicity. We also compare our extinctions to those derived from fitting the spectral energy distribution (SED) using the Bayesian Extinction and Stellar Tool (BEAST) for NGC 7793 and find systematically lower extinctions from SED-fitting as compared to isochrone matching., Comment: 22 pages, 14 figures, accepted by ApJ

Published
2018

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