Search Publications
Detailed Study of Stars and Gas in a z = 8.3 Massive Merger with Extreme Dust Conditions
Harshan, Anishya; Tripodi, Roberta; Martis, Nicholas S. +15 more
We present galaxy MACS0416-Y1 at zspec = 8.312 as observed by the CAnadian NIRISS Unbiased Cluster Survey. MACS0416-Y1 has been shown to have extreme dust properties; thus, we study the physical properties and star formation histories of its resolved components. Overall, we find that MACS0416-Y1 is undergoing a star formation burst in t…
The Magellan M2FS Spectroscopic Survey of High-redshift Galaxies: The Brightest Lyman-break Galaxies at z ∼ 6
Jiang, Linhua; Ning, Yuanhang; Pan, Zhiwei +2 more
We present a study of a sample of 45 spectroscopically confirmed, UV luminous galaxies at z ∼ 6. They were selected as bright Lyman-break galaxies (LBGs) using deep multiband optical images in more than 2 deg2 of the sky, and subsequently identified via their strong Lyα emission. The majority of these LBGs span an absolute UV magnitude …
Comparison of the Chemical Compositions between the Bright and Faint Red Clumps for the Metal-poor and Metal-rich Populations in the Milky Way Bulge
Lee, Young-Wook; Hong, Seungsoo; Lim, Dongwook
We examined the double red clump (RC) observed in the Galactic bulge, interpreted as a difference in distance ("X-shaped bulge scenario") or in chemical composition ("multiple population scenario"). To verify chemical differences between the RC groups, we performed low-resolution spectroscopy for RC and red giant branch (RGB) stars using Gemini-So…
Data-driven Stellar Intrinsic Colors and Dust Reddenings for Spectrophotometric Data: From the Blue-edge Method to a Machine Learning Approach
Ren, Yi; Wang, Shu; Jiang, Biwei +4 more
Intrinsic colors (ICs) of stars are essential for studies on both stellar physics and dust reddening. In this work, we developed an XGBoost model to predict ICs with the atmospheric parameters T eff,
Identifying Plasma Fractionation Processes in the Chromosphere Using IRIS
Stangalini, Marco; Long, David M.; Testa, Paola +7 more
The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the first ionization potential (FIP) of the different elements. This produces a FIP bias, wherein elements with a low FIP are preferentially enhanced in the corona compared to their photospheric ab…
The Star Formation History of Nearby Galaxies: A Machine Learning Approach
Tian, Hao; Yang, Ming; Liu, Chao +2 more
Reproducing color–magnitude diagrams (CMDs) of star-resolved galaxies is one of the most precise methods for measuring the star formation history (SFH) of nearby galaxies back to the earliest time. The upcoming big data era poses challenges to the traditional numerical technique in its capacity to deal with vast amounts of data, which motivates us…
Molecular Bubble and Outflow in S Mon Revealed by Multiband Data Sets
Xu, Ye; Liu, Dejian; Hao, Chaojie +8 more
We identify a molecular bubble, and study the star formation and its feedback in the S Mon region, using multiple molecular lines, young stellar objects (YSOs), and infrared data. We revisit the distance to S Mon, ∼722 ± 9 pc, using Gaia Data Release 3 parallaxes of the associated Class II YSOs. The bubble may be mainly driven by a massive binary …
Lyman Continuum Leakers at z > 3 in the GOODS-S Field: Starburst or Not?
Zheng, Zhen-Ya; Yuan, Fang-Ting; Lin, Ruqiu +2 more
We investigate the star-forming properties of 23 Lyman continuum (LyC) leakers at z > 3 in the Great Observatories Origins Deep Survey-South field based on a systematic review of LyC observations from the literature. Using data from the Hubble Space Telescope and the James Webb Space Telescope, we construct the spectral energy distributions for…
Modeling Transition Region Hot Loops on the Sun: The Necessity of Rapid, Complex Spatiotemporal Heating and Nonequilibrium Ionization
Bahauddin, Shah Mohammad; Bradshaw, Stephen J.
The study examines the heating profile of hot solar transition region loops, particularly focusing on transient brightenings observed in IRIS 1400 Å slit-jaw images. The findings challenge the adequacy of simplistic, singular heating mechanisms, revealing that the heating is temporally impulsive and requires a spatially complex profile with multip…
What Holes in the Gas Distribution of Nearly Face-on Galaxies Can Tell Us about the Host Disk Parameters: The Case of the NGC 628 Southeast Superbubble
Mayya, Y. D.; Silich, S.; Zaragoza-Cardiel, J. +1 more
Here we explore the impact of all major factors, such as the nonhomogeneous gas distribution, galactic rotation, and gravity, on the observational appearance of superbubbles in nearly face-on spiral galaxies. The results of our 3D numerical simulations are compared to the observed gas column density distribution in the largest southeast superbubbl…