Search Publications
Numerical Modeling of Latitudinal Gradients for Galactic Cosmic-Ray Protons during Solar Minima: Comparing with Ulysses Observations
Qin, Gang; Shen, Zhenning; Zuo, Pingbing +2 more
The latitudinal gradients of galactic cosmic-ray (GCR) protons measured by Ulysses during two successive minima provide a unique opportunity to study the modulation effects in polar regions of the heliosphere. In this work, a GCR modulation model based on numerically solving the Parker transport equation is used to study the latitudinal distributi…
Revisiting the Fundamental Parameters of 49 New Star Clusters in Gaia DR2
Li, Zhongmu; Chen, Jing; Deng, Yangyang
Reliable fundamental parameters of star clusters such as distance modulus, metallicity, age, extinction, and binary fraction are of key importance for astrophysical studies. Although a lot of new star clusters were identified from the data of, e.g., Gaia Data Release 2 (Gaia DR2), the fundamental parameters of many clusters were not determined rel…
Magnetohydrodynamic Modeling of the Solar Corona with an Effective Implicit Strategy
Shen, Fang; Feng, Xueshang; Xiang, Changqing +4 more
In this paper, we design an effective and robust model to solve the 3D single-fluid solar wind plasma magnetohydrodynamics (MHD) problem of low plasma β. This MHD model is formulated on a six-component composite grid system free of polar singularities. The computational domain ranges from the solar surface to the super-Alfvénic region. As common t…
WawHelioGlow: A Model of the Heliospheric Backscatter Glow. I. Model Definition
Bzowski, M.; Kubiak, M. A.; Kowalska-Leszczynska, I. +1 more
The helioglow is the fluorescence of interstellar atoms inside the heliosphere, where they are excited by the solar EUV emission. So far, the helioglow of interstellar H and He has been detected. The helioglow features a characteristic distribution in the sky, which can be used to derive the properties of both interstellar neutral (ISN) gas and th…
The Extinction and Distance of the MBM Molecular Clouds at High Galactic Latitude
Ren, Yi; Jiang, Biwei; Zhao, He +1 more
Based on the accurate color excess {E}_{{{\rm{G}}}_{\mathrm{BP}},{{\rm{G}}}_{\mathrm{RP}}}$ of more than 4 million stars and the {E}_{\mathrm{NUV},{{\rm{G}}}_{\mathrm{BP}}}$ of more than 1 million stars from Sun et al., the distance and extinction of the molecular clouds (MCs) in the Magnani-Blitz-Mundy catalog at ∣b∣ > 20° are studied in combi…
Quiet-Sun Mg II h and k Line Profiles Derived from IRIS Full-Sun Mosaics. I. Reference Profiles and Center-to-limb Variation
Heinzel, Petr; Gunár, Stanislav; Koza, Július +2 more
We derived high-precision reference profiles of the Mg II h and k lines that represent the quiet Sun during a minimum of the solar activity. To do so, we used the broad catalog of full-Sun mosaics obtained by the Interface Region Imaging Spectrograph (IRIS). To minimize the influence of the local variations due to the on-disk solar features and to…
Superresolution Reconstruction of Severely Undersampled Point-spread Functions Using Point-source Stacking and Deconvolution
Zemcov, Michael; Symons, Teresa; Bock, James +4 more
Point-spread function (PSF) estimation in spatially undersampled images is challenging because large pixels average fine-scale spatial information. This is problematic when fine-resolution details are necessary, as in optimal photometry where knowledge of the illumination pattern beyond the native spatial resolution of the image may be required. H…
High-redshift Narrow-line Seyfert 1 Galaxies: A Candidate Sample
Stalin, C. S.; Rakshit, Suvendu; Shin, Jaejin +1 more
The study of narrow-line Seyfert 1 galaxies (NLS1s) is now mostly limited to low redshift (z < 0.8) because their definition requires the presence of the Hβ emission line, which is redshifted out of the spectral coverage of major ground-based spectroscopic surveys at z > 0.8. We studied the correlation between the properties of Hβ and Mg II …
WawHelioGlow: A Model of the Heliospheric Backscatter Glow. II. The Helioglow Buildup and the Potential Significance of the Anisotropy in the Solar EUV Output
Bzowski, M.; Kubiak, M. A.; Kowalska-Leszczynska, I. +1 more
The helioglow is the fluorescence of interstellar atoms inside the heliosphere, where they are excited by the solar EUV. Because the mean free path between collisions for interstellar gas is comparable to the size of the heliosphere, the distribution function of this gas inside the heliosphere strongly varies in space and with time and is non-Maxw…
TIMES. I. A Systematic Observation in Multiple Molecular Lines toward the Orion A and Ophiuchus Clouds
Cho, Jungyeon; Choi, Minho; Choi, Yunhee +16 more
We have used the Taeduk Radio Astronomy Observatory to observe the Orion A and Ophiuchus clouds in the J = 1-0 lines of 13CO, C18O, HCN, HCO+, and N2H+ and the J = 2-1 line of CS. The fully sampled maps with uniform noise levels are used to create moment maps. The variations of the line intens…