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Related papers: Star Formation in Ultrafaint Dwarfs: Continuous or…

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[Abridged]Ultra-faint dwarfs (UFDs) are expected to be the relics of the earliest galaxies forming in the Universe. Observations show the presence of a stellar halo around them, which can give precious insights into the evolution of UFDs.…

Astrophysics of Galaxies · Physics 2025-01-29 Lapo Querci , Andrea Pallottini , Lorenzo Branca , Stefania Salvadori

We present the star formation history of UGCA 290, a galaxy with properties intermediate between Blue Compact Dwarfs and Dwarf Irregulars. This galaxy is particularly interesting because its young stellar population is extremely similar to…

Astrophysics · Physics 2009-11-07 Mary M. Crone , Regina E. Schulte-Ladbeck , Laura Greggio , Ulrich Hopp

We present evolutionary synthesis models of starbursts on top of old stellar populations to investigate in detailed time evolution the relation between Ha luminosity and star formation rate (SFR). The models show that several effects have…

Astrophysics · Physics 2009-11-06 Peter M. Weilbacher , Uta Fritze-v. Alvensleben

Recent discoveries of a significant population of bright galaxies at cosmic dawn $\left(z \gtrsim 10\right)$ have enabled critical tests of cosmological galaxy formation models. In particular, the bright end of the galaxy UV luminosity…

We explore the radial variation of star formation histories in dwarf galaxies simulated with Feedback In Realistic Environments (FIRE) physics. The sample contains 9 low-mass field dwarfs with M_ star = 10^5 - 10^7 M_sun from previous FIRE…

Unsharp-mask images of HI emission from 36 dwarf irregular (dIrr) galaxies illustrate star formation in dispersed clouds and on the rims of large cavities. The cavities can extend for a radial scalelength and typically have circular or…

Astrophysics of Galaxies · Physics 2026-04-07 Bruce G. Elmegreen , Deidre A. Hunter

We investigate how star-forming galaxies typically assemble their masses at high redshift. Using the deep multi-wavelength coverage of the GOODS dataset, we measure stellar mass of a large sample of star-forming galaxies at z~4 and 5, and…

Observational evidence has been mounting over the past decade that at least some luminous (~2 L*) galaxies have formed nearly all of their stars within a short period of time only 1-2x10^9 years after the Big Bang. These are examples of the…

Astrophysics · Physics 2010-11-11 Elizabeth J. McGrath , Alan Stockton , Gabriela Canalizo

We introduce an effective framework to model star-formation burstiness and use it to jointly fit galaxy UV luminosity functions (UVLFs), clustering, and H$\alpha$/UV ratios, providing the first robust empirical evidence that early galaxies…

We present novel constraints on the underlying galaxy formation physics (e.g., mass loading factor, star formation history, metal retention) at $z\gtrsim7$ for the low-mass ($M_*\sim10^5$ M$_\odot$) Local Group ultra-faint dwarf galaxy…

Astrophysics of Galaxies · Physics 2023-09-01 Nathan R. Sandford , David H. Weinberg , Daniel R. Weisz , Sal Wanying Fu

We present an analysis of bursty star-formation histories (SFHs) of 346 star-forming galaxies at $1\lesssim z<7$, selected from JWST/NIRSpec G395M and PRISM spectroscopy provided by the CEERS and RUBIES surveys. We analyze the correlation…

IRAC data have long implied that early ($z\gtrsim6$) galaxies often have very high specific star formation rates (sSFR$\gtrsim$30 Gyr$^{-1}$), but JWST data have shown that at least some early galaxies are forming stars far less vigorously.…

Astrophysics of Galaxies · Physics 2024-10-04 Ryan Endsley , John Chisholm , Daniel P. Stark , Michael W. Topping , Lily Whitler

We interpret the peculiar super-solar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 ($z=10.6$) using our state-of-the-art chemical evolution models. The observed CNO ratios can be…

Astrophysics of Galaxies · Physics 2024-01-23 Chiaki Kobayashi , Andrea Ferrara

We consider evolution of interstellar clouds in Local Group dwarf spheroidal galaxies (dSphs) in the context of their observed star formation histories. The Local Group dSphs generally experienced initial bursts of star formations in their…

Astrophysics · Physics 2009-10-31 H. Hirashita

We perform calculations of pre-main sequence evolution of stars from 1 to $85 M_{\odot}$ with growing accretion rates $\dot{M}$. The values of $\dot{M}$ are taken equal to a constant fraction $\tilde{f}$ of the rates of the mass outflows…

Astrophysics · Physics 2016-08-30 R. Behrend , A. Maeder

Context. In the Local Group, dwarf spheroidal galaxies (dSphs) and ultra-faint dwarf galaxies (UFDs) exhibit large velocity dispersions. These values are generally attributed to the presence of substantial amounts of dark matter (DM), in…

We present first results from a new, multiyear, time domain survey of young stars in the North America Nebula complex using the Palomar Transient Factory. Our survey is providing an unprecedented view of aperiodic variability in young stars…

Solar and Stellar Astrophysics · Physics 2026-04-01 Krzysztof Findeisen , Lynne Hillenbrand , Eran Ofek , David Levitan , Branimir Sesar , Russ Laher , Jason Surace

The metallicity distribution function (MDF) of the Galactic bulge features a multi-peak shape, with a metal-poor peak at [Fe/H]=-0.3 dex and a metal-rich peak at [Fe/H]=+0.3 dex. This bimodality is also seen in [alpha/Fe] versus [Fe/H]…

Astrophysics of Galaxies · Physics 2024-05-22 M. Molero , F. Matteucci , E. Spitoni , A. Rojas-Arriagada , R. M. Rich

Winds are predicted to be ubiquitous in low-mass, actively star-forming galaxies. Observationally, winds have been detected in relatively few local dwarf galaxies, with even fewer constraints placed on their timescales. Here, we compare…

Astrophysics of Galaxies · Physics 2018-04-11 Kristen B. W. McQuinn , Evan D. Skillman , Taryn N. Heliman , Noah P. Mitchell , Tyler Kelley

JWST has measured an unprecedented abundance of galaxies above $z\gtrsim 4-5$, whose formation and evolution are still difficult to reconcile within traditional galaxy evolution models in a $\Lambda$CDM framework. Here, we present a study…