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Related papers: Geometrically Derived Timescales for Star Formatio…

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We present a detailed study of the Circinus Galaxy, investigating its star formation, dust and gas properties both in the inner and outer disk. To achieve this, we obtained high-resolution Spitzer mid-infrared images with the IRAC (3.6,…

Astrophysics of Galaxies · Physics 2015-06-05 Bi-Qing For , Bärbel Koribalski , Tom Jarrett

Broadband B and R and H-alpha images have been obtained with the 4.1-m SOAR telescope atop Cerro Pachon, Chile for 29 spiral galaxies in the Pegasus I galaxy cluster and for 18 spirals in non-cluster environments. Pegasus I is a spiral-rich…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 James A. Rose , Paul Robertson , Jesse Miner , Lorenza Levy

The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time. Thanks to the WFC3 grism on HST it is now possible to measure this beyond the local Universe. Here we present the spatial…

Initial conditions for star formation in clusters are estimated for protostars whose masses follow the initial mass function (IMF) from 0.05 to 10 solar masses. Star-forming infall is assumed equally likely to stop at any moment, due to gas…

Astrophysics of Galaxies · Physics 2015-05-18 Philip C. Myers

Many early-type galaxies have been detected at wavelengths of 24 to 160 micron, but the emission is usually dominated by heating from an AGN or from the evolved stellar population. Here we present Spitzer MIPS observations of a sample of…

Astrophysics · Physics 2009-11-13 L M Young , G J Bendo , Danielle Lucero

We study the Kennicutt-Schmidt relation between average star formation rate and average cold gas surface density in the Hi dominated ISM of nearby spiral and dwarf irregular galaxies. We divide the galaxies into grid cells varying from…

Astrophysics of Galaxies · Physics 2015-06-24 Sambit Roychowdhury , Mei-Ling Huang , Guinevere Kauffmann , Jing Wang , Jayaram N. Chengalur

One of the scenarios for the formation of grand-design spiral arms in disky galaxies involves their interactions with a satellite or another galaxy. Here we consider another possibility, where the perturbation is instead due to the…

Astrophysics of Galaxies · Physics 2016-12-28 Marcin Semczuk , Ewa L. Lokas , Andres del Pino

We examined offsets between HII regions and molecular clouds belonging to spiral arms of a late type spiral galaxy NGC 4254 (M99). We used a high resolution CO(1-0) image obtained by Nobeyama Millimeter Array (NMA) and an H-alpha image. We…

Astrophysics · Physics 2015-06-24 Fumi Egusa , Yoshiaki Sofue , Hiroyuki Nakanishi

Galaxy morphology is shaped by stellar activity, feedback, gas and dust properties, and interactions with surroundings, and can therefore provide insight into these processes. In this paper, we study the spatial offsets between stellar and…

We present radio and infrared observations indicating on-going star formation activity inside the $\sim2-5$ pc circumnuclear ring at the Galactic center. Collectively these measurements suggest a continued disk-based mode of on-going star…

Astrophysics of Galaxies · Physics 2015-08-06 F. Yusef-Zadeh , M. Wardle , M. Sewilo , D. A. Roberts , I. Smith , R. Arendt , W. Cotton , J. Lacy , S. Martin , M. W. Pound , M. Rickett , M. Royster

Scale-invariant morphology parameters applied to atomic hydrogen maps (HI) of galaxies can be used to quantify the effects of tidal interaction or star-formation on the ISM. Here we apply these parameters, Concentration, Asymmetry,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 B. W. Holwerda , N. Pirzkal , W. J. G. de Blok , S-L. Blyth

We present the results of a galaxy-wide study of molecular gas and star formation in a sample of 76 HII regions in the nearby spiral galaxy NGC 300. We have measured the molecular gas at 250 pc scales using pointed CO(J=2-1) observations…

Astrophysics of Galaxies · Physics 2015-06-19 Christopher M. Faesi , Charles J. Lada , Jan Forbrich , Karl Menten , Herve Bouy

Fragmentation and evolution for the molecular shells of the compact HII regions are less explored compared to their evolved counterparts. We map nine compact HII regions with a typical diameter of 0.4 pc that are surrounded by molecular…

We analyze three nearby spiral galaxies - NGC 1097, NGC 1566, and NGC 3627 - using images from the DustPedia database in seven infrared bands (3.6, 8, 24, 70, 100, 160, and 250 micron). For each image, we perform photometric decomposition…

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…

Astrophysics of Galaxies · Physics 2016-10-19 Allison Merritt , Pieter van Dokkum , Roberto Abraham , Jielai Zhang

We built a multi-wavelength dataset for galaxies from the Local Volume HI Survey (LVHIS), which comprises 82 galaxies. We also select a sub-sample of ten large galaxies for investigating properties in the galactic outskirts. The LVHIS…

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

The observed discrete multiple stellar populations and internal abundance spreads in r- and s-process elements within globular clusters (GCs) have been suggested to be explained self-consistently by discrete star formation events over a…

Astrophysics of Galaxies · Physics 2019-07-03 Kenji Bekki

Tidal Dwarf Galaxies (TDGs) are objects presently forming from gas which has been expelled from their parent galaxies during an interaction. We observed the CO emission of a sample of 11 TDGs, of which 8 were detected. The CO is found at…

Astrophysics · Physics 2007-05-23 U. Lisenfeld , J. Braine , O. Vallejo , P. -A. Duc , S. Leon , E. Brinks , V. Charmandaris