Search Publications
TYC 3340-2437-1: A Quadruple System with a Massive Star
Fang, Min; Jin, Chichuan; Liu, Chao +11 more
Hierarchical massive quadruple systems are ideal laboratories for examining the theories of star formation, dynamical evolution, and stellar evolution. The successive mergers of hierarchical quadruple systems might explain the mass gap between neutron stars and black holes. Looking for light curves of O-type binaries identified by LAMOST, we find …
The Low-mass Stellar Initial Mass Function in Nearby Ultrafaint Dwarf Galaxies
van der Marel, Roeland P.; Wyse, Rosemary F. G.; Sacchi, Elena +3 more
The stellar initial mass function (IMF) describes the distribution of stellar masses that form in a given star formation event. The long main-sequence lifetimes of low-mass stars mean that the IMF in this regime (below ∼ 1 M ⊙) can be investigated through star counts. Ultrafaint dwarf galaxies are low-luminosity systems with ancient, me…
DESI Emission-line Galaxies: Unveiling the Diversity of [O II] Profiles and Its Links to Star Formation and Morphology
Brooks, D.; Doel, P.; Gutierrez, G. +34 more
We study the [O II] profiles of emission-line galaxies (ELGs) from the Early Data Release of the Dark Energy Spectroscopic Instrument (DESI). To this end, we decompose and classify the shape of [O II] profiles with the first two eigenspectra derived from principal component analysis. Our results show that DESI ELGs have diverse line profiles, whic…
The Regulation of the Solar Wind Electron Heat Flux by Wave–Particle Interactions
Verscharen, Daniel; Chen, Christopher H. K.; Maksimovic, Milan +11 more
The solar wind electrons carry a significant heat flux into the heliosphere. The weakly collisional state of the solar wind implicates collisionless processes as the primary factor that constrains nonthermal features of the velocity distribution function (VDF), including the heat flux. Previous observational work suggests that the electron VDF som…
Digging into the Ultraviolet Luminosity Functions of Galaxies at High Redshifts: Galaxies Evolution, Reionization, and Cosmological Parameters
Lei, Lei; Fan, Yi-Zhong; Wang, Yi-Ying +2 more
Thanks to the successful performance of the James Webb Space Telescope, our understanding of the epoch of reionization of the Universe has been advanced. The ultraviolet luminosity functions (UV LFs) of galaxies span a wide range of redshifts, not only revealing the connection between galaxies and dark matter (DM) halos but also providing informat…
The Newly Discovered Nova Super-remnant Surrounding Recurrent Nova T Coronae Borealis: Will it Light Up during the Coming Eruption?
Walter, Frederick M.; Shara, Michael M.; Lanzetta, Kenneth M. +7 more
A century or less separates the thermonuclear-powered eruptions of recurrent novae (RNe) in the hydrogen-rich envelopes of massive white dwarfs. The colliding ejecta of successive RN events are predicted to always generate very large (tens of parsecs) super-remnants; only two examples are currently known. T CrB offers an excellent opportunity to t…
The Hubble Constant Anchor Galaxy NGC 4258: Metallicity and Distance from Blue Supergiants
Li, Siyang; Riess, Adam G.; Yuan, Wenlong +5 more
A quantitative spectroscopic study of blue supergiant stars in the Hubble constant anchor galaxy NGC 4258 is presented. The non-LTE analysis of Keck I telescope LRIS spectra yields a central logarithmic metallicity (in units of the solar value) of [Z] = ‑0.05 ± 0.05 and a very shallow gradient of ‑(0.09 ± 0.11) r/r 25 with respect to ga…
CLASSY. XI. Tracing Neutral Gas Properties Using UV Absorption Lines and 21 cm Observations
Martin, Crystal L.; McQuinn, Kristen B. W.; Skillman, Evan D. +15 more
Rest-frame far-ultraviolet (FUV) observations from JWST are revolutionizing our understanding of the high-z galaxies that drove reionization and the mechanisms by which they accomplished it. To fully interpret these observations, we must be able to diagnose how properties of the interstellar medium (ISM; e.g., column density, covering fraction, an…
Stacking and Analyzing MOSDEF Galaxies by Spectral Types: Implications for Dust Geometry and Galaxy Evolution
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +12 more
We examine star formation and dust properties for a sample of 660 galaxies at 1.37 ≤ z ≤ 2.61 in the MOSDEF survey by dividing them into groups with similarly shaped spectral energy distributions (SEDs). For each group, we combine the galaxy photometry into a finely sampled composite SED, and stack their spectra. This method enables the study of m…
Spatially Resolved Analysis of Stellar Populations in NGC 2992: Impact of Active Galactic Nucleus Feedback
Chen, Yanmei; Li, Zhiyuan; Wang, Junfeng +1 more
In NGC 2992, a galaxy-scale ionized gas outflow driven by active galactic nuclei (AGNs) has long been recognized, yet its impact on the host galaxy has remained elusive. In this paper, we utilize data from the archival Very Large Telescope/MUSE to present a spatially resolved analysis of stellar populations in this galaxy. Two different stellar po…