Search Publications
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…
A Rapid Sequence of Solar Energetic Particle Events Associated with a Series of Extreme-ultraviolet Jets: Solar Orbiter, STEREO-A, and Near-Earth Spacecraft Observations
Lario, D.; Zhukov, A. N.; Jebaraj, I. C. +28 more
A series of solar energetic electron (SEE) events was observed from 2022 November 9 to November 15 by Solar Orbiter, STEREO-A, and near-Earth spacecraft. At least 32 SEE intensity enhancements at energies >10 keV were clearly distinguishable in Solar Orbiter particle data, with 13 of them occurring on November 11. Several of these events were a…
Infrared Spectroscopic and Physical Properties of Methanol Ices—Reconciling the Conflicting Published Band Strengths of an Important Interstellar Solid
Gerakines, Perry A.; Yarnall, Yukiko Y.; Hudson, Reggie L.
Infrared spectroscopic observations have established the presence of solid methanol (CH3OH) in the interstellar medium and in solar system ices, but the abundance of frozen CH3OH cannot be deduced without accurate band strengths, optical constants, and reference spectra. In this paper we identify disagreements, omissions, and…
Ly Halo Properties and Dust in the Circumgalactic Medium of z ∼ 2 Star-forming Galaxies
Shapley, Alice E.; Steidel, Charles C.; Reddy, Naveen A. +7 more
We present Keck Cosmic Web Imager integral-field unit observations around extended Lyα halos of 27 typical star-forming galaxies with redshifts 2.0 < z < 3.2 drawn from the MOSFIRE Deep Evolution Field survey. We examine the average Lyα surface brightness profiles in bins of star formation rate (SFR), stellar mass (M *), age, stel…
Stellar Cycle and Evolution of Polar Spots in an M+WD Binary
Liu, Jifeng; Wang, Song; Zhao, Xinlin +5 more
Stellar activity cycles reveal continuous relaxation and induction of magnetic fields. The activity cycle is typically traced through the observation of cyclic variations in total brightness or Ca H&K emission flux of stars, as well as cyclic variations in the orbital periods of binary systems. In this work, we report the identification of a s…