相关论文: Deep HST Imaging of Sextans A I. The Spatially Res…

We present a measurement of the star formation history of Sextans A, based on WFPC2 photometry that is 50% complete to V=27.5 (M_V ~+ 1.9) and I=27.0. The star formation history and chemical enrichment history have been measured through…

We investigate the relationship between the spatial distributions of stellar populations and of neutral and ionized gas in the Local Group dwarf irregular galaxy Sextans A. This galaxy is currently experiencing a burst of localized star…

We build a catalog of massive (M>$8~$M$_\odot$) main sequence stars in the \mbox{metal-poor} ($\sim0.1~$Z$_\odot$) dwarf irregular galaxy Sextans A. HST WFC3 UV photometry in the 275 and 336 nm wideband filters is arranged in a…

We present spectroscopic observations of a massive globular cluster in the dwarf irregular galaxy Sextans B, discovered by us on Hubble Space Telescope Wide Field and Planetary Camera 2 (HST WFPC2) images. Long-slit spectra were obtained…

We present the star formation history (SFH) of the Sextans dwarf spheroidal galaxy based on deep archive $B$,$I$ photometry taken with Suprime-Cam at Subaru telescope focusing our analysis on the inner region of the galaxy, fully located…

We present results from deep and very spatially extended CTIO/DECam $g$ and $r$ photometry (reaching out to $\sim$ 2 mag below the oldest MSTO and covering $\sim$ 20 deg$^2$) around the Sextans dSph. We use this data-set to study the…

We have examined the ratio of blue to red (B/R) supergiants in the dwarf irregular galaxy Sextans A. The supergiants were identified in previously published stellar photometry measured from Hubble Space Telescope imaging. The high…

We present the star formation history and chemical evolution of the Sextans dSph dwarf galaxy as a function of galactocentric distance. We derive these from the $VI$ photometry of stars in the $42' \times 28'$ field using the SMART model…

We study the evolved stellar population of the galaxy Sextans A. This galaxy is one of the lowest metallicity dwarfs in which variable asymptotic giant branch stars have been detected, suggesting that little metal enrichment took place…

HI observations of the Local Group dwarf irregular galaxies Sextans A and B, obtained with the Karoo Array Telescope (KAT-7) are presented. The KAT-7 wide field of view and excellent surface brightness sensitivity allows us to verify the…

We present a study of the metal-poor (~6% Z_sun) massive (>8 M_sun) main-sequence star population in the star-forming dwarf galaxy Sextans A. By modeling near-UV to near-IR photometry of individual stars using the Bayesian Extinction and…

The Hubble Deep Field (HDF) is the deepest set of multicolor optical photometric observations ever undertaken, and offers a valuable data set with which to study galaxy evolution. Combining the optical WFPC2 data with ground-based…

We present a sample of 24 local star-forming galaxies observed with broad- and narrow-band photometry from the Hubble Space Telescope, that are part of the GOALS survey of local luminous and ultra-luminous infrared galaxies. With…

We present a detailed analysis of Hubble Space Telescope (HST), Wide Field Camera 3 (WFC3) G141 grism spectroscopy for seven star-forming regions of the highly magnified lensed starburst galaxy RCSGA 032727-132609 at z=1.704. We measure the…

We present a detailed study of the stellar and HI structure of the dwarf irregular galaxies SextansA and SextansB, members of the NGC3109 association. We use newly obtained deep (r~26.5) and wide field g,r photometry to extend the Surface…

We analyze the resolved stellar populations of 473 massive star-forming galaxies at 0.7 < z < 1.5, with multi-wavelength broad-band imaging from CANDELS and Halpha surface brightness profiles at the same kiloparsec resolution from 3D-HST.…

We report on deep near-infrared observations obtained with the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope (HST) of the first five confirmed gravitational lensing events discovered by the Herschel Astrophysical Terahertz…

With both nebular- and stellar-derived abundances of $\lesssim$ 1/10 Zsun and low foreground extinction, Sextans A is a prime candidate to replace the Small Magellanic Cloud as reservoir of metal-poor massive stars and reference to study…

The near-star environment around obscured stars is very dynamic. Many classes of stars show evidence for winds, disks, inflows and outflows with many phenomena occurring simultaneously. These processes are involved in stellar evolution,…

A new method of determining galaxy star-formation histories (SFHs) is presented. Using the method, the feasibility of recovering SFHs with multi-band photometry is investigated. The method divides a galaxy's history into discrete time…