English
Related papers

Related papers: DDO 43: A Prototypical Dwarf Irregular Galaxy?

200 papers

We study the neutral hydrogen distribution and kinematics in the Local Group dwarf irregular galaxy IC 1613 and compare them with the ionized gas distribution and stellar content of the galaxy. We discuss several mechanisms which may be…

The nearby galaxy HIZSS003 was recently discovered during a blind HI survey of the zone of avoidance (Henning et al. 2000). Follow up VLA as well as optical and near-IR imaging and spectroscopy (Massey et al. 2003; Silva et al. 2005)…

Astrophysics · Physics 2009-11-10 Ayesha Begum , Jayaram N. Chengalur , I. D. Karachentsev , M. E. Sharina

The pressures of giant HII regions in 6 dwarf Irregular galaxies are a factor of ~10 larger than the average pressures of the corresponding galaxy disks, obtained from the stellar and gaseous column densities. Either the visible HII regions…

Astrophysics · Physics 2009-10-31 B. G. Elmegreen , D. A. Hunter

We present Giant Meterwave Radio Telescope (GMRT) HI 21cm images of a nearby dwarf irregular galaxy NGC 3741 (M_B ~ -13.13 mag) which show it to have a gas disk that extends to ~ 8.3 times its Holmberg radius. This makes it probably the…

Astrophysics · Physics 2009-11-10 Ayesha Begum , Jayaram N. Chengalur , I. D. Karachentsev

Several measures of galaxy size and mass obtained from the neutral hydrogen mapping of 70 dwarf irregular galaxies presented in Paper I (Hoffman et al. 1996) are compared statistically to those for the set of all available HI-mapped dwarfs…

Astrophysics · Physics 2009-10-28 E. E. Salpeter , G. L. Hoffman

We present ground-based and HST WFPC2 imaging of the nearby low surface brightness dwarf spheroidal galaxy DDO 44. For the first time DDO 44 was resolved into stars. The resulting color-magnitude diagram for about 1290 stars shows the red…

Dwarf irregulars (dIrrs) are among the most common type of galaxy in the Universe. They typically have gas-rich, low surface-brightness, metal-poor, and relatively-thick disks. Here we summarize the current state of our knowledge of the…

Astrophysics of Galaxies · Physics 2024-02-28 Deidre A. Hunter , Bruce G. Elmegreen , Suzanne C. Madden

We present a catalog of holes and shells in the neutral atomic hydrogen (\HI) of 41 gas-rich dwarf galaxies in LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The \HI Nearby Galaxy Survey). We analyzed their properties as…

Astrophysics of Galaxies · Physics 2020-07-22 Nau Raj Pokhrel , Caroline E. Simpson , Ioannis Bagetakos

The Draco dwarf spheroidal galaxy (dSph), with its apparent immense mass to light ratio and compact size, holds many clues to the nature of the enigmatic dark matter. Here we present deep photometric studies of this dwarf galaxy, undertaken…

Astrophysics · Physics 2008-11-26 Mathieu Segall , Rodrigo Ibata , Michael Irwin , Nicolas Martin , Scott Chapman

We use a dedicated 0.7-m telescope to image the halos of 119 galaxies in the Local Volume to $\mu_r \sim 28-30$ mag/arcsec$^2$. The sample is primarily from the 2MASS Large Galaxy Atlas and extended to include nearby dwarf galaxies and more…

We present Giant Metrewave Radio Telescope (GMRT) observations for three (viz., DDO 68, SDSS J2104-0035 and UGC 772) of the six most metal-deficient actively star-forming galaxies known. Although there is a debate as to whether these…

Astrophysics · Physics 2009-11-13 Ekta , Jayaram N. Chengalur , S. A. Pustilnik

We describe results of a multi-spectral study of a blue compact dwarf galaxy in Virgo. The object was observed with broad-band and H$\alpha$ imaging, UV observations, and radio synthesis. Our data were combined with published optical…

Astrophysics · Physics 2007-05-23 N. Brosch , E. Almoznino , L. Hoffman

We present the star formation history of the extremely metal-poor dwarf galaxy DDO 68, based on our photometry with the Advanced Camera for Surveys. With a metallicity of only $12+\log(O/H)=7.15$ and a very isolated location, DDO 68 is one…

Astrophysics of Galaxies · Physics 2016-10-12 E. Sacchi , F. Annibali , M. Cignoni , A. Aloisi , T. Sohn , M. Tosi , R. P. van der Marel , A. J. Grocholski , B. James

We use Subaru Suprime-Cam and VLT FORS1 photometry of the dwarf galaxy DDO210 to study the global stellar content and structural properties of a transition-type galaxy (with properties intermediate between dwarf irregular and dwarf…

Astrophysics · Physics 2009-11-11 Alan W. McConnachie , Nobuo Arimoto , Mike Irwin , Eline Tolstoy

We have used dedicated 0.7m telescopes in California and Israel to image the halos of ~200 galaxies in the Local Volume to 29 mag/sq arcsec, the sample mainly drawn from the 2MASS Large Galaxy Atlas (LGA). We supplement the LGA sample with…

We present radio and optical observations of Holmberg I (HoI), a member of the M81 group of galaxies (distance 3.6Mpc). HoI is a low-mass, low surface- brightness dwarf galaxy. High-resolution multi-array VLA HI observations reveal a…

Our GMRT HI observations of the ultra diffuse galaxy (UDG) UGC 2162, projected $\sim$ 300 kpc from the centre of the M77 group, reveal it to a have an extended HI disk (R$_{HI}$/R$_{25}$ $\sim$ 3.3) with a moderate rotational velocity…

Astrophysics of Galaxies · Physics 2019-07-31 Chandreyee Sengupta , T. C. Scott , Aeree Chung , O. Ivy Wong

Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral galaxies viewed edge-on. Two subsystems can be distinguished…

Astrophysics · Physics 2007-05-23 N. A. Tikhonov

We have examined the stellar structure of 10 nearby, low stellar mass (10^6 to 6 x 10^7 Msolar) dwarf irregular galaxies by fitting ellipses as a function of surface brightness on ultra-deep V images. These are compared to far ultraviolet…

Astrophysics of Galaxies · Physics 2026-05-04 Deidre A. Hunter , Bruce G. Elmegreen

We report the discovery of a new faint dwarf galaxy, GHOSTS I, using HST/ACS data from one of our GHOSTS (Galaxy Halos, Outer disks, Substructure, Thick disk, and Star clusters) fields. Its detected individual stars populate an…