scholarly journals The disc-averaged star formation relation for Local Volume dwarf galaxies

2018 ◽  
Vol 480 (1) ◽  
pp. 210-222 ◽  
Author(s):  
Á R López-Sánchez ◽  
C D P Lagos ◽  
T Young ◽  
H Jerjen
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Local Volume

scholarly journals COMPARISON OF Hα AND UV STAR FORMATION RATES IN THE LOCAL VOLUME: SYSTEMATIC DISCREPANCIES FOR DWARF GALAXIES

2009 ◽  
Vol 706 (1) ◽  
pp. 599-613 ◽  
Author(s):  
Janice C. Lee ◽  
Armando Gil de Paz ◽  
Christy Tremonti ◽  
Robert C. Kennicutt ◽  
Samir Salim ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Local Volume

scholarly journals THE ACS NEARBY GALAXY SURVEY TREASURY. VIII. THE GLOBAL STAR FORMATION HISTORIES OF 60 DWARF GALAXIES IN THE LOCAL VOLUME

2011 ◽  
Vol 739 (1) ◽  
pp. 5 ◽  
Author(s):  
Daniel R. Weisz ◽  
Julianne J. Dalcanton ◽  
Benjamin F. Williams ◽  
Karoline M. Gilbert ◽  
Evan D. Skillman ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Nearby Galaxy ◽  
Local Volume ◽  
Star Formation Histories

scholarly journals Neutral Hydrogen in Nearby Dwarf Galaxies

2018 ◽  
Vol 14 (S344) ◽  
pp. 288-291
Author(s):  
Bärbel S. Koribalski
Keyword(s):  
Star Formation ◽  
Mixed Type ◽  
Phased Array ◽  
Dwarf Galaxies ◽  
Neutral Hydrogen ◽  
Gas Content ◽  
Wide Field ◽  
Local Volume ◽  
Phased Array Feeds ◽  
Compact Array

AbstractHere I briefly highlight our studies of the gas content, kinematics and star formation in nearby dwarf galaxies (D < 10 Mpc) based on the ‘Local Volume Hi Survey’ (LVHIS, Koribalski et al. 2018), which was conducted with the Australia Telescope Compact Array (ATCA). The LVHIS sample consists of nearly 100 galaxies, including new discoveries, spanning a large diversity in size, shape, mass and degree of peculiarity. The hydrogen properties of dwarf galaxies in two nearby groups, Sculptor and CenA / M83, are analysed and compared with many rather isolated dwarf galaxies. Around 10% of LVHIS galaxies are transitional or mixed-type dwarf galaxies (dIrr/dSph), the formation of which is explored. — I also provide a brief update on WALLABY Early Science, where we focus on studying the Hi properties of galaxies as a function of environment. WALLABY (Dec < +30 degr, z < 0.26) is conducted with the Australian SKA Pathfinder (ASKAP), a ∽6-km diameter array of 36 × 12-m dishes, each equipped with wide-field (30 sq degr) Chequerboard Phased Array Feeds.

scholarly journals The Halos and Environments of Nearby Galaxies (HERON) Survey

2016 ◽  
Vol 11 (S321) ◽  
pp. 186-189 ◽  
Author(s):  
R. Michael Rich ◽  
Noah Brosch ◽  
James Bullock ◽  
Andreas Burkert ◽  
Michelle Collins ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Spiral Galaxies ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
General Survey ◽  
Tidal Disruption ◽  
Local Volume ◽  
Low Surface Brightness ◽  
Nearby Galaxies

AbstractWe 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 dwarf galaxies and more distant giant ellipticals. Low surface brightness halos exceeding 50 kpc in diameter are found only in galaxies more luminous than L*, and classic interaction signatures are relatively infrequent. Halo diameter is correlated with total galaxy luminosity. Extended low surface brightness halos are present even in galaxies as faint as MV = - 18. Edge-on galaxies with boxy bulges tend to lack extended spheroidal halos, while those with large classical bulges exhibit extended round halos, supporting the notions that boxy or barlike bulges originate from disks. Most face-on spiral galaxies present features that appear to be irregular extensions of spiral arms, although rare cases show smooth boundaries with no sign of star formation. Although we serendipitously discovered a dwarf galaxy undergoing tidal disruption in the halo of NGC 4449, we found no comparable examples in our general survey. A search for similar examples in the Local Volume identified hcc087, a tidally disrupting dwarf galaxy in the Hercules Cluster, but we do not confirm an anomalously large half-light radius reported for the dwarf VCC 1661.

scholarly journals The role of mergers and interactions in driving the evolution of dwarf galaxies over cosmic time

2020 ◽  
Vol 500 (4) ◽  
pp. 4937-4957 ◽  
Author(s):  
G Martin ◽  
R A Jackson ◽  
S Kaviraj ◽  
H Choi ◽  
J E G Devriendt ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Large Fraction ◽  
Structural Evolution ◽  
Cosmic Time ◽  
Stellar Mass ◽  
High Mass ◽  
Key Drivers ◽  
Mass Assembly

ABSTRACT Dwarf galaxies (M⋆ &lt; 109 M⊙) are key drivers of mass assembly in high-mass galaxies, but relatively little is understood about the assembly of dwarf galaxies themselves. Using the NewHorizon cosmological simulation (∼40 pc spatial resolution), we investigate how mergers and fly-bys drive the mass assembly and structural evolution of around 1000 field and group dwarfs up to z = 0.5. We find that, while dwarf galaxies often exhibit disturbed morphologies (5 and 20 per cent are disturbed at z = 1 and z = 3 respectively), only a small proportion of the morphological disturbances seen in dwarf galaxies are driven by mergers at any redshift (for 109 M⊙, mergers drive under 20 per cent morphological disturbances). They are instead primarily the result of interactions that do not end in a merger (e.g. fly-bys). Given the large fraction of apparently morphologically disturbed dwarf galaxies which are not, in fact, merging, this finding is particularly important to future studies identifying dwarf mergers and post-mergers morphologically at intermediate and high redshifts. Dwarfs typically undergo one major and one minor merger between z = 5 and z = 0.5, accounting for 10 per cent of their total stellar mass. Mergers can also drive moderate star formation enhancements at lower redshifts (3 or 4 times at z = 1), but this accounts for only a few per cent of stellar mass in the dwarf regime given their infrequency. Non-merger interactions drive significantly smaller star formation enhancements (around two times), but their preponderance relative to mergers means they account for around 10 per cent of stellar mass formed in the dwarf regime.

scholarly journals NIHAO – XXV. Convergence in the cusp-core transformation of cold dark matter haloes at high star formation thresholds

2020 ◽  
Vol 499 (2) ◽  
pp. 2648-2661
Author(s):  
Aaron A Dutton ◽  
Tobias Buck ◽  
Andrea V Macciò ◽  
Keri L Dixon ◽  
Marvin Blank ◽  
...  
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Galaxy Formation ◽  
Cold Dark Matter ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Good Description ◽  
Good Match ◽  
Virial Mass ◽  
Density Threshold

ABSTRACT We use cosmological hydrodynamical galaxy formation simulations from the NIHAO project to investigate the response of cold dark matter (CDM) haloes to baryonic processes. Previous work has shown that the halo response is primarily a function of the ratio between galaxy stellar mass and total virial mass, and the density threshold above which gas is eligible to form stars, n[cm−3]. At low n all simulations in the literature agree that dwarf galaxy haloes are cuspy, but at high n ≳ 100 there is no consensus. We trace halo contraction in dwarf galaxies with n ≳ 100 reported in some previous simulations to insufficient spatial resolution. Provided the adopted star formation threshold is appropriate for the resolution of the simulation, we show that the halo response is remarkably stable for n ≳ 5, up to the highest star formation threshold that we test, n = 500. This free parameter can be calibrated using the observed clustering of young stars. Simulations with low thresholds n ≤ 1 predict clustering that is too weak, while simulations with high star formation thresholds n ≳ 5, are consistent with the observed clustering. Finally, we test the CDM predictions against the circular velocities of nearby dwarf galaxies. Low thresholds predict velocities that are too high, while simulations with n ∼ 10 provide a good match to the observations. We thus conclude that the CDM model provides a good description of the structure of galaxies on kpc scales provided the effects of baryons are properly captured.

scholarly journals Episodic model for star formation history and chemical abundances in giant and dwarf galaxies

2016 ◽  
Vol 462 (4) ◽  
pp. 3739-3750 ◽  
Author(s):  
Suma Debsarma ◽  
Tanuka Chattopadhyay ◽  
Sukanta Das ◽  
Daniel Pfenniger
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Star Formation History ◽  
Chemical Abundances ◽  
Formation History
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