ACHANDRASTUDY OF THE ROSETTE STAR-FORMING COMPLEX. III. THE NGC 2237 CLUSTER AND THE REGION'S STAR FORMATION HISTORY

The objective of this work is to study how active galactic nuclei (AGN) influence star formation in host galaxies. We present a detailed investigation of the star-formation history and conditions of a z = 2.57 massive radio galaxy based on VLT/X-shooter and ALMA observations. The deep rest-frame ultraviolet spectrum contains photospheric absorption lines and wind features indicating the presence of OB-type stars. The most significantly detected photospheric features are used to characterize the recent star formation: neither instantaneous nor continuous star-formation history is consistent with the relative strength of the Si IIλ1485 and S Vλ1502 absorption. Rather, at least two bursts of star formation took place in the recent past, at 6+1-2 Myr and ≳20 Myr ago, respectively. We deduce a molecular H2 gas mass of (3.9 ± 1.0) × 1010 M⊙ based on ALMA observations of the [C I] 3P2−3P1 emission. The molecular gas mass is only 13% of its stellar mass. Combined with its high star-formation rate of (1020-170+190 M⊙ yr-1, this implies a high star-formation efficiency of (26 ± 8) Gyr−1 and a short depletion time of (38 ± 12) Myr. We attribute the efficient star formation to compressive gas motions in order to explain the modest velocity dispersions (⩽55 km s−1) of the photospheric lines and of the star-forming gas traced by [C I]. Because of the likely very young age of the radio source, our findings suggest that vigorous star formation consumes much of the gas and works in concert with the AGN to remove any residual molecular gas, and eventually quenching star formation in massive galaxies.

Download Full-text

Star-Forming Galaxies at Cosmic Noon

Annual Review of Astronomy and Astrophysics ◽

10.1146/annurev-astro-032620-021910 ◽

2020 ◽

Vol 58 (1) ◽

pp. 661-725 ◽

Cited By ~ 2

Author(s):

Natascha M. Förster Schreiber ◽

Stijn Wuyts

Keyword(s):

Star Formation ◽

Galaxy Evolution ◽

Star Formation History ◽

Massive Galaxies ◽

Star Forming ◽

Dense Cores ◽

Gravitational Instabilities ◽

James Webb Space Telescope ◽

Formation History ◽

Large Telescopes

Ever deeper and wider look-back surveys have led to a fairly robust outline of the cosmic star-formation history, which culminated around [Formula: see text]; this period is often nicknamed “cosmic noon.” Our knowledge about star-forming galaxies at these epochs has dramatically advanced from increasingly complete population censuses and detailed views of individual galaxies. We highlight some of the key observational insights that influenced our current understanding of galaxy evolution in the equilibrium growth picture: ▪ Scaling relations between galaxy properties are fairly well established among massive galaxies at least out to [Formula: see text], pointing to regulating mechanisms already acting on galaxy growth. ▪ Resolved views reveal that gravitational instabilities and efficient secular processes within the gas- and baryon-rich galaxies at [Formula: see text] play an important role in the early buildup of galactic structure. ▪ Ever more sensitive observations of kinematics at [Formula: see text] are probing the baryon and dark matter budget on galactic scales and the links between star-forming galaxies and their likely descendants. ▪ Toward higher masses, massive bulges, dense cores, and powerful AGNs and AGN-driven outflows are more prevalent and likely play a role in quenching star formation. We outline emerging questions and exciting prospects for the next decade with upcoming instrumentation, including the James Webb Space Telescope and the next generation of extremely large telescopes.

Download Full-text

Recent Star Formation History of the Magellanic Clouds

Symposium - International Astronomical Union ◽

10.1017/s0074180900118649 ◽

1999 ◽

Vol 190 ◽

pp. 470-472

Author(s):

Eva K. Grebel ◽

Wolfgang Brandner

Keyword(s):

Star Formation ◽

Large Scale ◽

New Age ◽

Magellanic Clouds ◽

Star Formation History ◽

Star Forming ◽

Formation History ◽

History Of

A new age calibration of Cepheids and supergiants is used to study the large-scale recent star formation history of the LMC and the SMC. We find evidence for migration of star formation along the LMC bar as well as for the existence of long-lived (≈ 200 Myr) extended star-forming features.

Download Full-text

The 1.4-GHz cosmic star formation history at z < 1.3

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2019.6 ◽

2019 ◽

Vol 36 ◽

Author(s):

James E. Upjohn ◽

Michael J. I. Brown ◽

Andrew M. Hopkins ◽

Nicolas J. Bonne

Keyword(s):

Star Formation ◽

Luminosity Function ◽

Star Formation Rate ◽

Formation Rate ◽

Radio Continuum ◽

Star Formation History ◽

Star Forming ◽

Formation History ◽

Radio Measurements ◽

Radio Luminosity Function

AbstractWe measure the cosmic star formation history out to z = 1.3 using a sample of 918 radio-selected star-forming galaxies within the 2-deg2 COSMOS field. To increase our sample size, we combine 1.4-GHz flux densities from the VLA-COSMOS catalogue with flux densities measured from the VLA-COSMOS radio continuum image at the positions of I < 26.5 galaxies, enabling us to detect 1.4-GHz sources as faint as 40 μJy. We find that radio measurements of the cosmic star formation history are highly dependent on sample completeness and models used to extrapolate the faint end of the radio luminosity function. For our preferred model of the luminosity function, we find the star formation rate density increases from 0.017 M⊙ yr−1 Mpc−3 at z ∼ 0.225 to 0.092 M⊙ yr−1 Mpc−3 at z ∼ 1.1, which agrees to within 40% of recent UV, IR and 3-GHz measurements of the cosmic star formation history.

Download Full-text

Modelling Stellar Populations at High Redshift

Proceedings of the International Astronomical Union ◽

10.1017/s174392131102268x ◽

2010 ◽

Vol 6 (S277) ◽

pp. 158-165

Author(s):

Claudia Maraston

Keyword(s):

Star Formation ◽

High Redshift ◽

Stellar Populations ◽

Star Formation History ◽

Population Modelling ◽

Massive Galaxies ◽

Star Forming ◽

Formation History ◽

Derived Properties ◽

Stellar Masses

AbstractStellar populations carry information about the formation of galaxies and their evolution up to the present epoch. A wealth of observational data are available nowadays, which are analysed with stellar population models in order to obtain key properties such as ages, star formation histories, stellar masses. Differences in the models and/or in the assumptions regarding the star formation history affect the derived properties as much as differences in the data. I shall review the interpretation of high-redshift galaxy data from a model perspective. While data quality dominates galaxy analysis at the highest possible redshifts (z > 5), population modelling effects play the major part at lower redshifts. In particular, I discuss the cases of both star-forming galaxies at the peak of the cosmic star formation history as well as passive galaxies at redshift below 1 that are often used as cosmological probes. Remarks on the bridge between low and high-z massive galaxies conclude the contribution.

Download Full-text

Stellar Populations and the Star Formation Histories of LSB Galaxies—Part I: Optical and HαImaging

Advances in Astronomy ◽

10.1155/2011/143698 ◽

2011 ◽

Vol 2011 ◽

pp. 1-18 ◽

Cited By ~ 22

Author(s):

James Schombert ◽

Tamela Maciel ◽

Stacy McGaugh

Keyword(s):

Star Formation ◽

Data Storage ◽

Star Formation History ◽

Star Forming ◽

Reduction Techniques ◽

Formation History ◽

History Of ◽

Star Formation Histories ◽

Baryonic Mass ◽

Lsb Galaxies

This paper presents optical and Hαimaging for a large sample of LSB galaxies selected from the PSS-II catalogs (Schombert et al., 1992). As noted in previous work, LSB galaxies span a range of luminosities () and sizes (), although they are consistent in their irregular morphology. Their Hαluminosities (L(Hα)) range from 1036to 1041 ergs s−1(corresponding to a range in star formation, using canonical prescriptions, from 10−5to 1 yr−1). Although their optical colors are at the extreme blue edge for galaxies, they are similar to the colors of dwarf galaxies (Van Zee, 2001) and gas-rich irregulars (Hunter and Elmegreen, 2006). However, their star formation rates per unit stellar mass are a factor of ten less than other galaxies of the same baryonic mass, indicating that they are not simply quiescent versions of more active star-forming galaxies. This paper presents the data, reduction techniques, and new philosophy of data storage and presentation. Later papers in this series will explore the stellar population and star formation history of LSB galaxies using this dataset.

Download Full-text

Galaxies in the first billion years: implications for re-ionization and the star formation history at z>6

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307010307 ◽

2006 ◽

Vol 2 (14) ◽

pp. 248-248

Author(s):

Andrew J. Bunker ◽

Elizabeth R. Stanway ◽

Laurence P. Eyles ◽

Richard S. Ellis ◽

Richard G. McMahon ◽

...

Keyword(s):

Star Formation ◽

Star Formation Rate ◽

Formation Rate ◽

Stellar Populations ◽

Star Formation History ◽

Star Forming ◽

Formation History ◽

Stellar Masses ◽

The Universe ◽

Selection Of

AbstractWe discuss the selection of star-forming galaxies at z≃6 through the Lyman-break technique. Spitzer imaging implies many of these contain older stellar populations (>200Myr) which produce detectable Balmer breaks. The ages and stellar masses (∼1010M⊙) imply that the star formation rate density at earlier epochs may have been significantly higher than at z≃6, and might have played a key role in re-ionizing the universe.

Download Full-text

Kinematics and dynamics of the luminous infrared galaxy pair NGC 5257/58 (Arp 240)

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834159 ◽

2018 ◽

Vol 621 ◽

pp. A25 ◽

Cited By ~ 2

Author(s):

I. Fuentes-Carrera ◽

M. Rosado ◽

P. Amram ◽

E. Laurikainen ◽

H. Salo ◽

...

Keyword(s):

Star Formation ◽

Energy Distribution ◽

Spectral Energy Distribution ◽

Star Formation History ◽

Spectral Energy ◽

Kinematics And Dynamics ◽

Ionized Gas ◽

Star Forming ◽

External Perturbations ◽

Formation History

Context. Encounters between galaxies modify their morphology, kinematics, and star formation history. The relation between these changes and external perturbations is not straightforward. The great number of parameters involved requires both the study of large samples and individual encounters where particular features, motions, and perturbations can be traced and analysed in detail. Aims. We analysed the morphology, kinematics, and dynamics of two luminous infrared spiral galaxies of almost equal mass, NGC 5257 and NGC 5258, in which star formation is mostly confined to the spiral arms, in order to understand interactions between galaxies of equivalent masses and star-forming processes during the encounter. Methods. Using scanning Fabry–Perot interferometry, we studied the contribution of circular and non-circular motions and the response of the ionized gas to external perturbations. We compared the kinematics with direct images and traced the star-forming processes and gravitational effects due to the presence of the other galaxy. The spectral energy distribution of each member of the pair was fitted. A mass model was fitted to the rotation curve of each galaxy. Results. Large, non-circular motions detected in both galaxies are associated with a bar, spiral arms, and HII regions for the inner parts of the galaxies, and with the tidal interaction for the outer parts of the discs. Bifurcations in the rotation curves indicate that the galaxies have recently undergone pericentric passage. The pattern speed of a perturbation of one of the galaxies is computed. Location of a possible corotation seems to indicate that the gravitational response of the ionized gas in the outer parts of the disc is related to the regions where ongoing star formation is confined. The spectral energy distribution fit indicates slightly different star formation history for each member of the pair. For both galaxies, a pseudo-isothermal halo better fits the global mass distribution.

Download Full-text