- ID:
- ivo://CDS.VizieR/J/ApJ/881/54
- Title:
- Masses of SNR progenitors in M83
- Short Name:
- J/ApJ/881/54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the ages of the young, resolved stellar populations at the locations of 237 optically identified supernova remnants in M83. These age distributions put constraints on the progenitor masses of the supernovae that produced 199 of the remnants. The other 38 show no evidence for having a young progenitor and are therefore good Type Ia SNR candidates. Starting from Hubble Space Telescope broadband imaging, we measured resolved stellar photometry of seven archival WFC3/UVIS fields in F336W, F438W, and F814W. We generate color-magnitude diagrams of the stars within 50pc of each SNR and fit them with stellar evolution models to obtain the population ages. From these ages we infer the progenitor mass that corresponds to the lifetime of the most prominent age within the past 50Myr. In this sample, there are 47 SNRs with best-fit progenitor masses >15M_{sun}_, and 5 of these are >15M_{sun}_ at 84% confidence. This is the largest collection of high-mass progenitors to date, including our highest-mass progenitor inference found so far, with a constraint of <8Myr. Overall, the distribution of progenitor masses has a power-law index of -3.0_-0.7_^+0.2^, steeper than Salpeter initial mass function (-2.35). It remains unclear whether the reason for the low number of high-mass progenitors is due to the difficulty of finding and measuring such objects or because only a fraction of very massive stars produce supernovae.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/156/27
- Title:
- Masses & radii of 4 VLM stars in EB systems
- Short Name:
- J/AJ/156/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing binaries (EBs) with one of the companions as very low-mass stars (VLMSs; or M dwarfs) are testbeds to substantiate stellar models and evolutionary theories. Here we present four EB candidates with F-type primaries, namely, SAO 106989, HD 24465, EPIC 211682657, and HD 205403, identified from different photometry missions, SuperWASP, Kilodegree Extremely Little Telescope (KELT), Kepler 2 (K2), and Solar Terrestrial Relations Observatory (STEREO). Using the high-resolution spectrograph PRL Advanced Radial velocity Abu-sky Search at the 1.2 m telescope at Mount Abu, Rajasthan, India, we hereby report the detection of four VLMSs as companions to the four EBs. We performed spectroscopic analysis and found the companion masses to be 0.256+/-0.005, 0.233+/-0.002, 0.599+/-0.017, and 0.406+/-0.005 M_{sun}_ for SAO 106989, HD 24465, EPIC 211682657, and SAO 106989B, respectively. We determined orbital periods of 4.39790+/-0.00001, 7.19635+/-0.00002, 3.142023+/-0.000003, and 2.444949+/-0.000001 days and eccentricities of 0.248+/-0.005, 0.208+/-0.002, 0.0097+/- 0.0008, and 0.002+/-0.002 for EBs SAO 106989, HD 24465, EPIC 211682657, and HD 205403, respectively. The radii derived by modeling the photometry data are 0.326+/-0.012 R_{sun}_ for SAO 106989, 0.244+/-0.001 R_{sun}_ for HD 24465B, 0.566+/-0.005 R_{sun}_ for EPIC 211682657B, and 0.444+/-0.014 R_{sun}_ for HD 205403B. The radii of HD 24465B and EPIC 211682657B have been measured by precise Kepler photometry and are consistent with theory within the error bars. However, the radii of SAO 106989B and HD 205403B, measured by KELT and STEREO photometry, are 17%-20% higher than those predicted by theory. A brief comparison of the results of the current work is made with the M dwarfs already studied in the literature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/2223
- Title:
- Mass estimation for FGK stars
- Short Name:
- J/MNRAS/445/2223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar evolutionary models simulate well binary stars when individual stellar mass and system metallicity are known. The mass can be derived directly from observations only in the case of multiple stellar systems, mainly binaries. Yet, the number of such stars for which accurate stellar masses are available is rather small. The main goal of this project is to provide realistic mass estimates for a homogeneous sample of about a thousand FGK single stars, using four different methods and techniques. We present the masses inferred according to each one of these methods as well as a final mass estimate consisting in the median of the four mass estimates. The procedures evaluated here include the use of stellar evolutionary models, mass-luminosity relation and surface gravity spectroscopic observations. By combining the results obtained with different methods, we determine the best mass value for each individual star, as well as the associated error budget. Our results confirm the expected consistency between the different mass estimation methods. None the less, for masses above 1.2M_{sun}_, the spectroscopic surface gravities seem to overestimate the mass. This result may be a consequence of the spectroscopic surface gravities used in this analysis. Nevertheless, this problem is minimized by the fact that we have several approaches available for deriving stellar masses. Moreover, we suggest an empirical procedure to overcome this issue.
- ID:
- ivo://CDS.VizieR/J/A+A/540/A57
- Title:
- Mass function of Quintuplet cluster
- Short Name:
- J/A+A/540/A57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The stellar mass function is a probe for a potential dependence of star formation on the environment. Only a few young clusters are known to reside within the central molecular zone and can serve as test-beds for star formation under the extreme conditions in this region. We determine the present-day mass function of the Quintuplet cluster, a young massive cluster in the vicinity of the Galactic centre. We use two epochs of high resolution near infrared imaging data obtained with NAOS/CONICA at the ESO VLT to measure the individual proper motions of stars in the Quintuplet cluster in the cluster reference frame. An unbiased sample of cluster members within a radius of 0.5pc from the cluster centre was established based on their common motion with respect to the field and a subsequent colour-cut. Initial stellar masses were inferred from four isochrones covering ages from 3 to 5Myr and two sets of stellar evolution models. For each isochrone, the present-day mass function of stars was determined for the full sample of main sequence cluster members using an equal number binning scheme. We find the slope of the present-day mass function in the central part of the Quintuplet cluster to be alpha=-1.68^+0.13^_-0.09_ for an approximate mass range from 5 to 40M_{sun}_, which is significantly flatter than the Salpeter slope of alpha=-2.35. The flattening of the present-day mass function may be caused by rapid dynamical evolution of the cluster in the strong Galactic centre tidal field. The derived mass function slope is compared to the values found in other young massive clusters in the Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/762/83
- Title:
- Massive early-type galaxies in K-band
- Short Name:
- J/ApJ/762/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use high-resolution K-band VLT/HAWK-I imaging over 0.25deg^2^ to study the structural evolution of massive early-type galaxies since z~2. Mass-selected samples, complete down to log(M/M_{sun}_)~10.7 such that "typical" (L*) galaxies are included at all redshifts, are drawn from pre-existing photometric redshift surveys. We then separate the samples into different redshift slices and classify them as late- or early-type galaxies on the basis of their specific star formation rate. Axis-ratio measurements for the ~400 early-type galaxies in the redshift range 0.6<z<1.8 are accurate to 0.1 or better. The projected axis-ratio distributions are then compared with lower redshift samples. We find strong evidence for evolution of the population properties: early-type galaxies at z>1 are, on average, flatter than at z<1 and the median projected axis ratio at a fixed mass decreases with redshift. However, we also find that at all epochs z<~2, the most massive early-type galaxies (log(M/M_{sun}_)>11.3) are the roundest, with a pronounced lack of galaxies that are flat in projection. Merging is a plausible mechanism that can explain both results: at all epochs, merging is required for early-type galaxies to grow beyond log(M/M_{sun}_)~11.3, and all early types over time gradually and partially lose their disk-like characteristics.
- ID:
- ivo://CDS.VizieR/J/ApJ/763/101
- Title:
- Massive field OB stars in the SMC
- Short Name:
- J/ApJ/763/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some theories of star formation suggest massive stars may only form in clustered environments, which would create a deficit of massive stars in low-density environments. Observationally, Massey (2002, Cat. II/236) finds such a deficit in samples of the field population in the Small and Large Magellanic Clouds, with an initial mass function (IMF) slope of {Gamma}_IMF_~4. These IMF measurements represent some of the largest known deviations from the standard Salpeter IMF slope of {Gamma}_IMF_=1.35. Here, we carry out a comprehensive investigation of the mass function above 20M_{sun}_ for the entire field population of the Small Magellanic Cloud (SMC), based on data from the Runaways and Isolated O Type Star Spectroscopic Survey of the SMC (RIOTS4). This is a spatially complete census of the entire field OB star population of the SMC obtained with the IMACS multi-object spectrograph and MIKE echelle spectrograph on the Magellan telescopes. Based on Monte Carlo simulations of the evolved present-day mass function, we find the slope of the field IMF above 20M_{sun}_ is {Gamma}_IMF_=2.3+/-0.4. We extend our IMF measurement to lower masses using BV photometry from the OGLE II survey. We use a statistical approach to generate a probability distribution for the mass of each star from the OGLE photometry, and we again find {Gamma}_IMF_=2.3+/-0.6 for stellar masses from 7M_{sun}_ to 20M_{sun}_. The discovery and removal of ten runaways in our RIOTS4 sample steepens the field IMF slope to {Gamma}_IMF_=2.8+/-0.5. We discuss the possible effects of binarity and star formation history on our results, and conclude that the steep field massive star IMF is most likely a real effect.
- ID:
- ivo://CDS.VizieR/J/other/Sci/359.69
- Title:
- Massive stars in 30 Dor
- Short Name:
- J/other/Sci/359.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 30 Doradus star-forming region in the Large Magellanic Cloud is a nearby analog of large star-formation events in the distant universe. We determined the recent formation history and the initial mass function (IMF) of massive stars in 30 Doradus on the basis of spectroscopic observations of 247 stars more massive than 15 solar masses (M_{sun}_). The main episode of massive star formation began about 8 million years (My) ago, and the star-formation rate seems to have declined in the last 1My. The IMF is densely sampled up to 200 Embedded Image and contains 32+/-12% more stars above 30M_{sun}_ than predicted by a standard Salpeter IMF. In the mass range of 15 to 200M_{sun}_, the IMF power-law exponent is 190^+0.37^_-0.26_, shallower than the Salpeter value of 2.35.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/70
- Title:
- Massive YSOs in the IR dark cloud G79.3+0.3
- Short Name:
- J/ApJ/876/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- G79.3+0.3 is an infrared dark cloud in the Cygnus-X complex that is home to massive deeply embedded young stellar objects (YSOs). We have produced a Submillimeter Array (SMA) 1.3mm continuum image and ^12^CO line maps of the eastern section of G79.3+0.3 in which we detect five separate YSOs. We have estimated physical parameters for these five YSOs and others in the vicinity of G79.3+0.3 by fitting existing photometry from Spitzer, Herschel, and ground-based telescopes to spectral energy distribution models. Through these model fits we find that the most massive YSOs seen in the SMA 1.3mm continuum emission have masses in the 5-6M_{sun}_ range. One of the SMA sources was observed to power a massive collimated ^12^CO outflow extending at least 0.94pc in both directions from the protostar, with a total mass of 0.83M_{sun}_ and a dynamical timescale of 23kyr.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A140
- Title:
- Mass limits on substellar companions
- Short Name:
- J/A+A/527/A140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The recently completed re-reduction of the Hipparcos data by van Leeuwen (2007, Astrophys. Space Library 350) makes it possible to search for the astrometric signatures of planets and brown dwarfs known from radial velocity surveys in the improved Hipparcos intermediate astrometric data. Our aim is to put more significant constraints on the orbital parameters which cannot be derived from radial velocities alone, i.e. the inclination and the longitude of the ascending node, than was possible before. The determination of the inclination in particular allows to calculate an unambiguous companion mass, rather than the lower mass limit which can be obtained from radial velocity measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/320/79
- Title:
- Mass-luminosity relation of low-mass stars
- Short Name:
- J/A+A/320/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To construct the MLR, empirical data for 56 stars in 30 low mass multiple systems, main sequence components of spectral class M0 and later were collected and processed. We considered only those systems where the determination of dynamical masses of components is possible, that is, where masses are derived directly from celestial mechanical considerations rather than from relations between mass and some observational parameter.
