Search Publications
TOI-1994b: A Low-mass Eccentric Brown Dwarf Transiting A Subgiant Star
Barclay, Thomas; Quinn, Samuel N.; Kane, Stephen R. +23 more
We present the discovery of TOI-1994b, a low-mass brown dwarf transiting a hot subgiant star on a moderately eccentric orbit. TOI-1994 has an effective temperature of ${7700}_{-410}^{+720}$ K, V magnitude of 10.51 mag and log(g) of ${3.982}_{-0.065}^{+0.067}$ . The brown dwarf has a mass of ${22.1}_{-2.5}^{+2.6}$ M J, a period of 4.034 …
A Strongly Lensed Dusty Starburst of an Intrinsic Disk Morphology at a Photometric Redshift of z ph > 7
Yan, Haojing; Cheng, Cheng; Ling, Chenxiaoji +3 more
We present COSBO-7, a strong millimeter source known for more than 16 yr that just revealed its near-to-mid-IR counterpart with the James Webb Space Telescope (JWST). The precise pinpointing by the Atacama Large Millimeter/submillimeter Array on the exquisite NIRCam and MIRI images show that it is a background source gravitationally lensed by a si…
The Near-infrared Ca II Triplet as a Stellar Activity Indicator: A Library and Comparative Study
Zhang, Yong; Huang, Xin; Zhang, Haotong +11 more
We have established and released a new stellar index library of the Ca II triplet, which serves as an indicator for characterizing the chromospheric activity of stars. The library is based on data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low-Resolution Spectroscopic Survey (LRS) Data Release 9. To better reflect …
Signatures of gas flows - I. Connecting the kinematics of the H I circumgalactic medium to galaxy rotation
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +5 more
The circumgalactic medium (CGM) hosts many physical processes with different kinematic signatures that affect galaxy evolution. We address the CGM-galaxy kinematic connection by quantifying the fraction of H I that is aligned with galaxy rotation with the equivalent width co-rotation fraction, $f_{\rm EWcorot}$. Using 70 quasar sightlines having H…
Constraints on Neutron Star Structure from the Clocked X-Ray Burster 1RXS J180408.9-342058
Nagataki, S.; Hashimoto, M.; Dohi, A. +3 more
Type I X-ray bursts are rapid-brightening transient phenomena on the surfaces of accreting neutron stars (NSs). Some X-ray bursts, called clocked bursters, exhibit regular behavior with similar light-curve profiles in their burst sequences. The periodic nature of clocked bursters has the advantage of constraining X-ray binary parameters and physic…
An overlooked source of uncertainty in the mass of the Milky Way
Riley, Alexander H.; Oman, Kyle A.
In the conventional approach to decomposing a rotation curve into a set of contributions from mass model components, the measurements of the rotation curve at different radii are taken to be independent. It is clear, however, that radial correlations are present in such data, for instance (but not only) because the orbital speed depends on the mas…
Spectroscopic Observations of the Solar Corona during the 2017 August 21 Total Solar Eclipse: Comparison of Spectral Line Widths and Doppler Shifts between Open and Closed Magnetic Structures
Landi, Enrico; Habbal, Shadia R.; Ding, Adalbert +5 more
The spectroscopic observations presented here were acquired during the 2017 August 21 total solar eclipse (TSE) with a three-channel partially multiplexed imaging spectrometer operating at extremely high orders (>50). The 4 R ⊙ extent of the slit in the north–south direction scanned the corona starting from the central meridian out t…
Identification of Carbon Stars from LAMOST DR7
Shi, Jianrong; Cui, Wenyuan; Li, Linlin +6 more
Carbon stars are excellent kinematic tracers of galaxies and play important roles in understanding the evolution of the Galaxy. Therefore, it is worthwhile to search for them in a large number of spectra. In this work, we build a new carbon star catalog based on the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) DR7 spectra. The…
The Galaxy–Galaxy Strong Lensing Cross Section and the Internal Distribution of Matter in ΛCDM Substructure
Mahler, Guillaume; Meneghetti, Massimo; Jauzac, Mathilde +3 more
Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in complex dynamical states, has also been used to map their dark matter (DM) substructures on smaller scales. D…
Realistic Uncertainties for Fundamental Properties of Asteroseismic Red Giants and the Interplay between Mixing Length, Metallicity, and ν max
Li, Yaguang; van Saders, Jennifer; Huber, Daniel +8 more
Asteroseismic modeling is a powerful way to derive stellar properties. However, the derived quantities are limited by built-in assumptions used in stellar models. This work presents a detailed characterization of stellar model uncertainties in asteroseismic red giants, focusing on the mixing-length parameter α MLT, the initial helium fr…