相关论文: Mass estimates in short-period compact binaries
We report the discovery of a very low mass binary system (primary mass <0.1 Msol) with a projected separation of ~5100 AU, more than twice that of the widest previously known system. A spectrum covering the 1-2.5 microns wavelength interval…
Simultaneous spectroscopic and photometric observations of the Z Cam type dwarf nova SY Cancri were used to obtain absolute flux calibrations. A comparison of the photometric calibration with a wide slit spectrophotometric calibration…
We present a method of determining lower limits on the masses of pre-main-sequence (PMS) stars and so constraining the PMS evolutionary tracks. This method uses the red-shifted absorption feature observed in some emission-line profiles of T…
We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the…
When modeling the population of merging binary black holes, analyses have generally focused on characterizing the distribution of primary (i.e. more massive) black holes in the binary, while simplistic prescriptions are used for the…
The complexity of composite spectra of close binary star system makes study of the spectra of their component stars extremely difficult. For this reason there exists very little information on the photospheric chemical composition of stars…
Contact binary star systems represent the long-lived penultimate phase of binary evolution. Population statistics of their physical parameters inform understanding of binary evolutionary pathways and end products. We use light curves and…
Young, intermediate-mass stars are experiencing renewed interest as targets for direct-imaging planet searches. However, these types of stars are part of multiple systems more often than not. Close stellar companions affect the formation…
We consider twin-peak quasi-periodic oscillations observed in the accreting low-mass neutron star binaries and explore restrictions to central compact object properties that are implied by various QPO models. For each model and each source,…
We report high-resolution optical spectroscopy of the low-mass X-ray binary V395 Car/2S 0921-630 obtained with the MIKE echelle spectrograph on the Magellan-Clay telescope. Our spectra are obtained near superior conjunction of the mass…
We model the phase-space of the kinematic tracers using general, smooth distribution functions to derive a conservative lower bound on the total mass within 150-200 kpc. By approximating the potential as Keplerian, the phase-space…
Low-mass pre-main sequence (PMS) stars are strong and variable X-ray emitters, as has been well established by EINSTEIN and ROSAT observatories. It was originally believed that this emission was of thermal nature and primarily originated…
This is the second paper that proposes a simple method for estimating mass ratios using the derivatives of light curves for overcontact binaries. In the first paper (Kouzuma 2023, ApJ, 958, 84) , we presented a method to estimate the mass…
Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a $ \sim 2-5M_{\odot} $ mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears…
Multiplicity is a key statistic for understanding the formation of very low mass (VLM) stars and brown dwarfs. Currently, the separation distribution of VLM binaries remains poorly constrained at small separations (< 1 AU), leading to…
The occurrence of planets in binary star systems has been investigated via a variety of techniques that sample a wide range of semi-major axes, but with a preponderance of such results applicable to planets with semi-major axes less than a…
Binary stars play a vital role in astrophysical research, as a good fraction of stars are in binaries. Binary fraction (BF) is known to change with stellar mass in the Galactic field, but such studies in clusters require binary…
Radial velocity studies of accreting binary stars commonly use accretion disk emission lines to determine the radial velocity of the primary star and therefore the mass ratio. These emission line radial velocity curves are often shifted in…
We present a population study of low- and intermediate-mass X-ray binaries (LMXBs) with neutron star accretors, performed using the detailed 1D stellar evolution code MESA. We identify all plausible Roche-lobe overflowing binaries at the…
The spectral absorption lines in early-type galaxies contain a wealth of information regarding the detailed abundance pattern, star formation history, and stellar initial mass function (IMF) of the underlying stellar population. Using our…