Search Publications
A New Type of Jet in a Polar Limb of the Solar Coronal Hole
Moon, Yong-Jae; Cho, Kyung-Suk; Kim, Yeon-Han +3 more
A new type of chromospheric jet in a polar limb of a coronal hole is discovered in the Ca II filtergram of the Solar Optical Telescope on board the Hinode. We identify 30 jets in a filtered Ca II movie with a duration of 53 minutes. The average speed at their maximum heights is found to be 132 ± 44 km s-1 ranging from 57 to 264 km s
Massive Young Stellar Objects and Outflow in the Infrared Dark Cloud G79.3+0.3
Zhang, Qizhou; Hora, Joseph L.; Laws, Anna S. E.
G79.3+0.3 is an infrared dark cloud in the Cygnus-X complex that is home to massive deeply embedded young stellar objects (YSOs). We have produced a Submillimeter Array (SMA) 1.3 mm continuum image and 12CO line maps of the eastern section of G79.3+0.3 in which we detect five separate YSOs. We have estimated physical parameters for thes…
Multiwavelength Study of the X-Ray Bright Supernova Remnant N300-S26 in NGC 300
Williams, Benjamin F.; Garofali, Kristen; Gross, Jacob +3 more
We present a multiwavelength examination of the supernova remnant (SNR) S26 in the nearby galaxy NGC 300 using data from Chandra X-ray Observatory, XMM-Newton X-ray Observatory, Hubble Space Telescope (HST), the Very Large Array, and the Australia Telescope Compact Array. We simultaneously fit all of the available X-ray data with a thermal plasma …
OGLE-2018-BLG-0022: First Prediction of an Astrometric Microlensing Signal from a Photometric Microlensing Event
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +68 more
In this work, we present the analysis of the binary microlensing event OGLE-2018-BLG-0022 that is detected toward the Galactic bulge field. The dense and continuous coverage with the high-quality photometry data from ground-based observations combined with the space-based Spitzer observations of this long timescale event enables us to uniquely det…
2FHL J0826.1-4500: Discovery of a Possible Shock-Cloud Interaction on the Western Edge of the Vela Supernova Remnant
Ajello, M.; Tibaldo, L.; Marchesi, S. +3 more
We report on the investigation of a very high-energy, Galactic γ-ray source recently discovered at >50 GeV using the Large Area Telescope on board Fermi. This object, 2FHL J0826.1-4500, displays one of the hardest >50 GeV spectra (photon index Γ γ ∼ 1.6) in the 2FHL catalog, and a follow-up observation with XMM-Newton has uncover…
Infrared Spectroscopy of the Recent Outburst in V1047 Cen (Nova Centauri 2005)
Udalski, A.; Mróz, P.; Munari, U. +14 more
Fourteen years after its eruption as a classical nova (CN), V1047 Cen (Nova Cen 2005) began an unusual re-brightening in 2019 April. The amplitude of the brightening suggests that this is a dwarf nova (DN) eruption in a CN system. Very few CNe have had DN eruptions within decades of the main CN outburst. The 14 yr separating the CN and DN eruption…
Structure of Our Galactic Bulge from CN Measurements
Lee, Jae-Woo
The double red clumps (DRCs) are now dominantly believed to be the strong observational line of evidence of the so-called X-shaped Galactic bar structures. Recently, Lee et al. reported a subtle mean δCN(3839) difference between the DRCs and suggested a dichotomic picture that can be seen in globular clusters: the faint red clump is the first gene…
Development of Hydrogen and Helium Proximity Zones around Quasars
Zheng, Wei; Meiksin, Avery; Syphers, David
Increasing evidence suggests that He II proximity profiles in the quasar spectra at z ∼ 3-4 are sensitive probes of quasar ages. But the development of their H I counterparts is difficult to trace and remains poorly constrained. We compare the UV spectra of 15 He II quasars with their high-resolution optical counterparts and find a significant cor…
Gravitational Lens System PS J0147+4630 (Andromeda’s Parachute): Main Lensing Galaxy and Optical Variability of the Quasar Images
Goicoechea, Luis J.; Shalyapin, Vyacheslav N.
Because follow-up observations of quadruple gravitational lens systems are of extraordinary importance for astrophysics and cosmology, we present single-epoch optical spectra and r-band light curves of PS J0147+4630. This recently discovered system mainly consists of four images ABCD of a background quasar around a foreground galaxy G that acts as…
A Study of the Merger History of the Galaxy Group HCG 62 Based on X-Ray Observations and Smoothed Particle Hydrodynamic Simulations
Hu, Dan; Xu, Haiguang; Zhu, Zhenghao +9 more
We chose the bright compact group HCG 62, which has been found to exhibit both excess X-ray emission and high Fe abundance to the southwest of its core, as an example to study the impact of mergers on chemical enrichment in the intragroup medium. We first reanalyze the high-quality Chandra and XMM-Newton archive data to search for evidence of addi…