相关论文: Locating Red Supergiants in the Galaxy NGC 6822

We present near-IR spectroscopy of red supergiant (RSG) stars in NGC 6822, obtained with the new VLT-KMOS instrument. From comparisons with model spectra in the J-band we determine the metallicity of 11 RSGs, finding a mean value of [Z] =…

Red supergiants (RSGs) are crucial for studying the properties and evolution of massive stars. It is representative to conduct a census of RSGs across the Local Group, which spans a broad metallicity range. However, identifying RSGs in…

A complete sample of red supergiant stars (RSGs) is important for studying their properties. Identifying RSGs in extragalatic field first requires removing the Galactic foreground dwarfs. The color-color diagram (CCD) method, specifically…

We present moderate-resolution spectroscopic observations of red supergiants (RSGs) in the low-metallicity Local Group galaxies NGC 6822 (Z = 0.4Zsun) and Wolf-Lundmark-Melotte (WLM; Z = 0.1Zsun). By combining these observations with…

We present a case study of using a novel method to identify red supergiant (RSG) candidates in NGC 6822, based on their 1.6 $\mu$m "H-bump". We collected 32 bands of photometric data for NGC 6822 ranging from optical to MIR. By using the…

This work establishes the most complete sample of red supergiants (RSGs) in twelve low-mass galaxies (WLM, IC 10, NGC 147, NGC 185, IC 1613, Leo A, Sextans B, Sextans A, NGC 6822, Pegasus Dwarf, SMC and LMC) of the Local Group, which forms…

We compile a catalog of 578 highly probable and 62 likely red supergiants (RSGs) of the Milky Way, which represents the largest list of Galactic RSG candidates designed for continuous follow-up to date. We match distances measured by Gaia…

Despite the many successes that modern massive star evolutionary theory has enjoyed, reproducing the apparent trend in the relative number of red supergiants (RSGs) and Wolf-Rayet (WR) stars has remained elusive. Previous estimates show the…

We have combined resolved stellar photometry from Hubble Space Telescope (\emph{HST}), \emph{Spitzer}, and \emph{Gaia} to identify red supergiant (RSG) candidates in NGC~6946, based on their colors, proper motions, visual morphologies, and…

Red supergiants (RSGs) are essential to understanding the evolution and the contribution to the interstellar medium of massive stars. However, the number of identified RSGs within the Milky Way is still limited mainly due to the difficulty…

Deep J, H, and K' images obtained with the Canada-France-Hawaii Telescope adaptive optics system are used to investigate the metallicity of red giant branch (RGB) stars in three fields in the disk of the Local Group dwarf irregular galaxy…

We present accurate and deep multi-band ($g,r,i$) photometry of the Local Group dwarf irregular galaxy NGC 6822. The images were collected with wide field cameras at 2m/4m- (INT,CTIO,CFHT) and 8m-class telescopes (SUBARU) covering a 2…

We have previously established, from a carbon star survey, that the Local Group dwarf irregular galaxy NGC 6822 is much larger than its central bright core. Four MegaCam fields are acquired to survey a 2$^\circ\times$ 2$^\circ$ area centred…

We present an extensive peakbagging effort on Kepler data of $\sim$50 red giant stars in the open star cluster NGC 6819. By employing sophisticated pre-processing of the time series and Markov Chain Monte Carlo techniques we extracted…

Aims: We calibrate spectroscopically the C- versus (vs.) M-type asymptotic giant branch (AGB) star selection made using near-IR photometry, and investigate the spatial distribution of the C/M ratio in NGC 6822, based on low resolution…

NGC 6822 is the closest isolated dwarf irregular galaxy to the Milky Way. Its proximity and stellar mass ($10^8 M_\odot$, large for a dwarf galaxy) allow for a detailed study of its kinematic properties. The red giant branch (RGB) stars at…

We investigate the red supergiant (RSG) content of the SMC and LMC using multi-object spectroscopy on a sample of red stars previously identified by {\it BVR} CCD photometry. We obtained high accuracy ($<1$ km s$^{-1}$) radial velocities…

We investigate the red supergiant (RSG) population of M31, obtaining radial velocities of 255 stars. These data substantiate membership of our photometrically-selected sample, demonstrating that Galactic foreground stars and extragalactic…

Red supergiants (RSGs) are important for our understanding of supernova progenitors, stellar populations, stellar evolution, mass loss and dust production. Extragalactic surveys of RSGs have a long history in the Local Group, but few…

We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at 8500 Angstroms was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line of sight…