Search arXivSearch

arXiv · astro-ph/9708056

Dust and Recent Star Formation in the Core of NGC5253

Abstract

(Abridged) Ultraviolet and optical narrow and broad band images of NGC5253 obtained with the HST WFPC2 are used to derive the properties of the dust distribution and the recent star formation history of this metal-poor dwarf galaxy. Corrections for the effects of dust are important in the center of NGC5253: dust reddening is markedly inhomogeneous across the galaxy's central 20" region. One of the most obscured regions coincides with the region of highest star formation activity in the galaxy: clouds of more than 9~magnitudes of optical depth at V enshroud a young (2.5~Myr old) stellar cluster in the region. Star formation has been active at least over the past 100 Myr in the core of the galaxy, as indicated by the age distribution of both the blue diffuse stellar population and the bright stellar clusters. The star formation is currently concentrated in a 6" region, about 5 Myr old and with a star formation intensity 10-100 times higher than the average within the central 20". The 2.5 Myr old cluster coincides with the peak intensity of the star formation; its mass may be as large as 10^6 solar masses, making this one a Super-Star-Cluster candidate.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D. Calzetti, G. Meurer, R. Bohlin, D. Garnett, A. Kinney, C. Leitherer, T. Storchi-Bergmann. 1997-08-06. Dust and Recent Star Formation in the Core of NGC5253. https://doi.org/10.1086/118609

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Cosmic Conundrums with Quantum Corrections

Darh energy was discovered over 25 years ago and we do not have an explanation of it. Dark matter comprises 95% of matter in the universe and we still don't know what it is. The Webb telescope has been finding fully formed galaxies with massive black holes millions of times the mass of the sun in the early universe and we don't have any explanation. A quantum density limitation will be used to solve these and other outstanding problems.

astro-ph

On binary pulsars and the force of gravity

The energy-momentum budget of the astrophysical systems can be studied by the exact local conservation equation derived by Landau and Lifshitz. We show that a similar equation is valid for the Einstein-Cartan gravity. We reanalyze a binary pulsar system using the Landau-Lifshitz conservation equation and show that the orbital period change rate can be completely understood as a curvature backreaction process. Taking into account the detailed theoretical and observational research of relativistic binary pulsar systems, especially the system of Hulse and Taylor, we conclude that general relativity and astrophysical observations rule out the existence of gravitational radiation. We comment upon the LIGO GW events and their alternative explanation, as well as the recent pulsar timing arrays data.

astro-ph

Oscillation frequencies and mode lifetimes in alpha Centauri A

We analyse our recently-published velocity measurements of alpha Cen A (Butler et al. 2004). After adjusting the weights on a night-by-night basis in order to optimize the window function to minimize sidelobes, we extract 42 oscillation frequencies with l=0 to 3 and measure the large and small frequency separations. We give fitted relations to these frequencies that can be compared with theoretical models and conclude that the observed scatter about these fits is due to the finite lifetimes of the oscillation modes. We estimate the mode lifetimes to be 1-2 d, substantially shorter than in the Sun.

astro-ph