Discovery of a young and massive stellar cluster: Spectrophotometric near-infrared study of Masgomas-1.

False colour image (blue=J, green=H, red=KS) for the massive stellar cluster Masgomas-1. Massive stars with spectral classification are marked with red circles.//LIRIS/ Telescopio William Herschel.
False colour image (blue=J, green=H, red=KS) for the massive stellar cluster Masgomas-1. Massive stars with spectral classification are marked with red circles.//LIRIS/ Telescopio William Herschel.
Advertised on
References
(2012), Ramírez Alegría, S., Marín-Franch, A., & Herrero, A. ,A&A, 541, A75

Recent near-infrared data have contributed to the discovery of new (obscured) massive stellar clusters and massive stellar populations in previously known clusters in our Galaxy. These discoveries lead us to view the Milky Way as an active star-forming machine.

Aims: The main purpose of this work is to  determine physically the main parameters (distance, size, total mass and age) of Masgomas-1, the first massive cluster discovered by our systematic search programme.

Methods: Using near-infrared (J, H, and KS) photometry we selected 23 OB-type and five red supergiant candidates for multi-object H- and K-band spectroscopy and spectral classification.

Results: Of the 28 spectroscopically observed stars, 17 were classified as OB-type, four as supergiants, one as an A-type dwarf star, and six as late-type giant stars. The presence of a supergiant population implies a massive nature of Masgomas-1, supported by our estimate of the cluster initial total mass of (1.94±0.28)·104 M⊙, obtained after integrating the cluster mass function. The distance estimate of (3.53±0.33) kpc locates the cluster closer than the Scutum-Centaurus base but still within that Galactic arm.  The presence of an O9V star and red supergiants in the same population indicates that the cluster age is in the range of 8 to 10 Myr.

News type
Research news

It may interest you

  • alpha_plot_density_gamma_b
    Research news
    The universal variability of the stellar initial mass function probed by the TIMER survey
    The universality of the stellar initial mass function (IMF) is one of the most widespread assumptions in modern Astronomy and yet, it might be flawed. While observations in the Milky Way generally support an IMF that is invariant with respect to the local conditions under which stars form, measurements of massive early-type galaxies systematically point towards a non-universal IMF. To bridge the gap between both sets of evidence, in this work we measured for the first time the low-mass end of the IMF from the integrated spectra of a Milky Way-like galaxy, NGC3351. We found that the slope of
    Advertised on
  • MaNGA galaxies
    Research news
    Constraints on the in situ and ex situ stellar masses in nearby galaxies obtained with artificial intelligence
    The hierarchical model of galaxy evolution suggests that mergers have a substantial impact on the intricate processes that drive stellar assembly within a galaxy. However, accurately measuring the contribution of accretion to a galaxy's total stellar mass and its balance with in situ star formation poses a persistent challenge, as it is neither directly observable nor easily inferred from observational properties. Using data from MaNGA, we present theory-motivated predictions for the fraction of stellar mass originating from mergers in a statistically significant sample of nearby galaxies
    Advertised on
  • Action space (normalized to the sum of the three actions of motion, Jtot) of Gaia RVS stars
    Research news
    The Metal-Poor Edge of the Milky Way’s Thin Disk
    The formation and evolution of the disk of our Galaxy, the Milky Way, remains an enigma in astronomy. In particular, the relationship between the thick disk and the thin disk —two key components of the Milky Way— is still unclear. Understanding the chemical and dynamical properties of the stars within these disks is crucial, especially in the parameter spaces where their characteristics overlap, such the metallicity regime around [Fe/H] ~ -0.7, which marks the metal-poor end of the thin disk, higher than that of the thick disk. This is often interpreted as an indication that the thin disk
    Advertised on