The supergiant shell with triggered star formation in the dwarf irregular galaxy IC 2574: neutral and ionized gas kinematics

Egorov, Oleg V.; Lozinskaya, T. A.; Моисеев, А. В.; Smirnov-Pinchukov, Grigorii V.

doi:10.1093/mnras/stu1369

Cited by 38 publications

(41 citation statements)

References 58 publications

(126 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These ages, together with the distance between the different SF episodes, imply velocities of 20 to 100 km s −1 for the blast wave caused by the SN explosions from the central post-starburst, to be able to ignite the current SF, in good agreement with the expansion velocities found for shells in dwarf galaxies (Walter 1999;Egorov et al 2014Egorov et al , 2017. Hence, the morphology and age distribution of the SF episode both indicate triggered SF in Tololo 1937-423, with the most recent SF episode triggered by the collective effects of stellar winds and SN explosions from the central post-starburst.…”

Section: Discussionsupporting

confidence: 79%

“…Holes in H i are thought to be created by feedback from massive stars: the supersonic flows generated by distant SN blast waves and/or stellar winds sweep up a shell of shocked neutral gas (Weaver et al 1977;McCray & Kafatos 1987;Tenorio-Tagle & Bodenheimer 1988;Weisz et al 2009b,a;Warren et al 2011;Bagetakos et al 2011). Evidence is accumulating that in the rims of these bubbles, new (secondary) star formation can occur (Lozinskaya 2002;Cannon et al 2005;Egorov et al 2014Egorov et al , 2017Cairós & González-Pérez 2017). In line with these findings, the ionized gas emission in Tololo 1937-423 could be tracing a secondary SF episode.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Probing star formation and feedback in dwarf galaxies

Cairós

González‐Pérez

2017

A&A

View full text Add to dashboard Cite

Context. Blue compact galaxies (BCG) are gas-rich, low-mass, small systems that form stars at unusually high rates. This makes them excellent laboratories for investigating the process of star-formation (SF) at galactic scales and the effects of massive stellar feedback on the interstellar (and intergalactic) medium. Aims. We analyzed the BCG Tololo 1937-423 using optical integral field spectroscopy to probe its morphology, stellar content, nebular excitation and ionization properties, and the kinematics of its warm ionized gas. Methods. Tololo 1937-423 was observed with the Visible Multi-Object Spectrograph at the Very Large Telescope. We took data in the wavelength range 4150-7400 Å, covering a field of view of 27 ′′ × 27 ′′ on the sky with a spatial sampling of 0 ′′ . 67. From these data we built maps in the continuum and brighter emission lines, diagnostic line ratio maps, and velocity dispersion fields. We also generated the integrated spectrum of the main H ii regions and young stellar clusters to determine reliable physical parameters and oxygen abundances. Results. We found that Tololo 1937-423 is currently undergoing an extended starburst. In the Hα maps we identified nine major clumps, aligned mostly northeast-southwest, and stretching to galactocentric distances ≥ 2 kpc. The galaxy presents a single continuum peak that is not cospatial with any knot in emission lines, indicating at least two relatively recent episodes of SF. The inhomogeneous dust distribution reachs its maximum [E(B-V)∼0.97] roughly at the position of the continuum peak. We found shocked regions in the galaxy outer regions and at the edges of the SF knots. The oxygen abundance, 12+log(O/H)∼8.20±0.1, is similar in all the SF regions, suggesting a chemically homogeneous ionized interstellar medium over spatial scales of several kpc. The ionized gas kinematics displays an overall regular rotation around a northwest-southeast axis, with a maximum velocity of 70±7 km s −1 . Conclusions. The morphology of the galaxy and the two different episodes of SF suggest a scenario of triggered (induced by supernova shock waves) SF acting in Tololo 1937-423. The inferred ages for the different SF episodes (∼13-80 Myr for the central post-starburst and 5-7 Myr for the ongoing SF) are consistent with triggered SF, with the most recent SF episode caused by the collective effect of stellar winds and supernova explosions from the central post-starburst. The velocity dispersion pattern, with higher velocity dispersions found at the edges of the SF regions, and shocked regions in the galaxy, also favor this scenario.

show abstract

Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Probing star formation and feedback in dwarf galaxies

Cairós

González‐Pérez

2017

A&A

View full text Add to dashboard Cite

show abstract

“…As Egorov et al (2014) show in their Fig. 1 for the SGS in IC 2754 in the Hα HST image, there are several clearly visible SF regions along the SGS borders.…”

Section: Sgs Expansion Timementioning

confidence: 72%

The extremely metal-poor galaxy DDO 68: the luminous blue variable, Hα shells and the most luminous stars

Pustilnik¹,

Макарова²,

Perepelitsyna³

et al. 2016

Mon. Not. R. Astron. Soc.

Self Cite

View full text Add to dashboard Cite

The paper presents new results of the ongoing study of the unusual Lynx-Cancer void galaxy DDO 68 with record-low-metallicity regions (12+log(O/H)∼7.14) of the current star formation (SF). They include: a) a new spectrum and photometry with the 6-m SAO RAS telescope (BTA) for the Luminous Blue Variable (LBV = DDO68-V1). Photometric data sets are complemented with those based on the Sloan Digital Sky Survey (SDSS) and the Hubble Space Telescope (HST) archive images; b) the analysis of the DDO 68 supergiant shell (SGS) and the prominent smaller Hα arcs/shells visible at the HST image coupled with kinematics maps in Hα obtained with the Fabry-Perot interferometer (FPI) at the BTA; c) the list of identified at the HST images of about 50 most luminous stars (−9.1 < M V < −6.0 mag) related to star-forming regions with the known extremely low O/H. This is intended to pave the path for the actual science with the next generation of giant telescopes. We confirm the earlier hints on significant variations of the LBV optical light deriving its amplitude of ∆V 3.7 mag for the first time. New data suggest that in 2008-2010 the LBV reached M V = -10.5 and probably underwent a giant eruption. We argue that the structure of star-forming complexes along the SGS ('Northern Ring') perimeter provides evidence for the sequential induced SF episodes caused by the shell gas instabilities and gravitational collapse. The variability of some DDO 68 luminous extremely metal-poor stars can be monitored with medium-size telescopes at sites with superb seeing.

show abstract

“…Evidence for superbubble merging from extragalactic studies is scarce, however, probably because of the low resolution (typically around 200 pc). Hα bubbles are found at the rims of HI supershells, however (Egorov et al 2014). Superbubble merging may produce significant net velocities in ejecta flows with respect to the driving massive-star group.…”

Section: Superbubble Size Distributions and Mergingmentioning

confidence: 97%

²⁶Al kinematics: superbubbles following the spiral arms?

Krause

Diehl

Bagetakos

et al. 2015

A&A

View full text Add to dashboard Cite

Context. High-energy resolution spectroscopy of the 1.8 MeV radioactive decay line of 26 Al with the SPI instrument onboard the INTEGRAL satellite has recently revealed that diffuse 26 Al has higher velocities than other components of the interstellar medium in the Milky Way. 26 Al shows Galactic rotation in the same sense as the stars and other gas tracers, but reaches excess velocities of up to 300 km s −1 . Aims. We investigate whether this result can be understood in the context of superbubbles, taking into account the statistics of young star clusters and H I supershells as well as the association of young star clusters with spiral arms. Methods. We derived energy output and 26 Al mass of star clusters as a function of the cluster mass by population synthesis from stellar evolutionary tracks of massive stars. Using the limiting cases of weakly and strongly dissipative superbubble expansion, we linked this to the size distribution of H I supershells and assessed the properties of possible 26 Al-carrying superbubbles. Results. 26 Al is produced by star clusters of all masses above ≈200 M , is roughly equally contributed over a logarithmic star cluster mass scale and strongly linked to the injection of feedback energy. The observed superbubble size distribution cannot be related to the star cluster mass function in a straightforward manner. To avoid the added volume of all superbubbles exceeding the volume of the Milky Way, individual superbubbles have to merge frequently. If any two superbubbles merge, or if 26 Al is injected off-centre into a larger HI supershell, we expect the hot 26 Al-carrying gas to obtain velocities of the order of the typical sound speed in superbubbles, ≈300 km s −1 before decay. For star formation coordinated by the spiral arm pattern which, inside co-rotation, is overtaken by the faster moving stars and gas, outflows from spiral arm star clusters would preferentially flow into the cavities that are inflated by previous star formation associated with this arm. These cavities would preferentially be located towards the leading edge of a given arm. Conclusions. This scenario might explain the 26 Al kinematics. The massive-star ejecta are expected to survive ≥10 6 yr before being recycled into next-generation stars.

show abstract

The supergiant shell with triggered star formation in the dwarf irregular galaxy IC 2574: neutral and ionized gas kinematics

Cited by 38 publications

References 58 publications

Probing star formation and feedback in dwarf galaxies

Probing star formation and feedback in dwarf galaxies

The extremely metal-poor galaxy DDO 68: the luminous blue variable, Hα shells and the most luminous stars

²⁶Al kinematics: superbubbles following the spiral arms?

Contact Info

Product

Resources

About

The supergiant shell with triggered star formation in the dwarf irregular galaxy IC 2574: neutral and ionized gas kinematics

Cited by 38 publications

References 58 publications

Probing star formation and feedback in dwarf galaxies

Probing star formation and feedback in dwarf galaxies

The extremely metal-poor galaxy DDO 68: the luminous blue variable, Hα shells and the most luminous stars

26Al kinematics: superbubbles following the spiral arms?

Contact Info

Product

Resources

About

²⁶Al kinematics: superbubbles following the spiral arms?