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Is Fermi 1544-0649 a Misaligned Blazar? Discovering the Jet Structure with Very Long Baseline Interferometry
Zhang, Zhongli; Chen, Wen; Cheng, Xiaopeng +8 more
Fermi J1544-0649 is a transient GeV source first detected during its GeV flares in 2017. Multiwavelength observations during the flaring time demonstrate variability and spectral energy distributions that are typical of a blazar. Other than the flare time, Fermi J1544-0649 is quiet in the GeV band and has looked rather like a quiet galaxy (2MASX J…
Sunspot numbers and proton events in solar cycles 19 to 24
Bromage, B. J. I.; Birch, M. J.
In this study we compare the mean annual sunspot numbers for the six most recent solar cycles (19 to 24) with the number of solar energetic proton events occurring in those years. Though most of the individual cycles exhibit quite strong correlations, when they are combined into a generic solar cycle the result is very significant (ρ = 0.98). For …
CME-related Large Decreases in the Differential Phase Delay of Tianwen-1 DOR Signals
Liu, Kaijun; Guo, Li; He, Qingbao +2 more
Differential phase delay is calculated for the differential one-way range (DOR) signals transmitted by Tianwen-1, the first Chinese Mars spacecraft that entered into the Mars orbit on 2021 February 10. Large decreases in the differential phase delay are identified in the DOR signals received by ground stations on 2021 March 23 and June 18. The dec…
The Ancient Globular Clusters of NGC 1291
Chandar, Rupali; Mok, Angus; Hixenbaugh, Kyle
We present a new catalog of 81 ancient globular clusters (GCs) in the early-type spiral (SB0/a) galaxy NGC 1291. Candidates have been selected from B, V, and I band images taken with the Hubble Space Telescope, which also reveal 17 younger (τ ≲ few × 100 Myr) clusters. The luminosity function shows a peaked shape similar to that found for GC syste…
Disentangling emission from star-forming regions in the Magellanic Clouds: Linking [O III]λ88 µm and 24 µm
Ramambason, L.; Lebouteiller, V.; Madden, S. C. +5 more
Context. The [O III]λ88 µm line is observed in many galaxies including our neighboring Magellanic Clouds and is a well-known tracer of H II regions, while the 24 µm continuum emission has often been used to trace warm dust in the ionized phases of galaxies. The association of both the [O III]λ88 µm line and 24 µm in galaxies to star formation moti…
Diagnosing Triggered Star Formation in the Galactic H II region Sh 2-142
Chen, Wen Ping; Gao, Yu; Sun, Yan +2 more
Stars are formed by gravitational collapse, spontaneously or, in some cases under the constructive influence of nearby massive stars, out of molecular cloud cores. Here we present an observational diagnosis of such triggered formation processes in the prominent H II region Sh 2-142, which is associated with the young star cluster NGC 7380, and wit…
Circumsolar Stellar Streams and Meteors in the Earth Atmosphere
Vereshchagin, S. V.; Chupina, N. V.; Tutukov, A. V.
On the basis of the Gaia data, we analyze the formation pattern of peripherical structures of planetary systems, the elements of which are dust, asteroids, comets, and unbound planets (the so-called ACP structures). These structures, "ACP spears," are as large as 30 to 104 pc; and, intersecting one with another, they permeate the Galaxy…
Mid-infrared and Maser Flux Variability Correlation in Massive Young Stellar Object G036.70+00.09
Ichikawa, Kohei; Uchiyama, Mizuho; Yonekura, Yoshinori +2 more
We present the discovery of the simultaneous flux variation of a massive young stellar object (MYSO) G036.70+00.09 (G036.70) both in the maser emission and mid-infrared (MIR; λ = 3-5 µm) bands. Using the ALLWISE and NEOWISE archival databases that cover a long time span of approximately 10 yr with a cadence of 6 months, we confirm that G036.…
The Solar Eruption of 2017 September 10: Wavy with a Chance of Protons
Pizzo, V. J.; de Koning, Curt A.; Seaton, Daniel B.
High-resolution SUVI images reveal an interesting new picture of particle acceleration in powerful solar eruptions. Typically, powerful solar eruptions include a coronal wave component, as well the traditional CME and flare components. At low solar altitudes, coronal waves refract downward, toward the solar surface, because of the slower Alfvén sp…
Hubble Space Telescope Captures UGC 12591: bulge/disc properties, star formation and 'missing baryons' census in a very massive and fast-spinning hybrid galaxy
Mukherjee, Dipanjan; Mirakhor, Mohammad; Dhiwar, Suraj +4 more
We present Hubble Space Telescope (HST) observations of the nearby, massive, highly rotating hybrid galaxy UGC 12591, along with observations in the UV to FIRbands. HST data in V, I, and H bands is used to disentangle the structural components. Surface photometry shows a dominance of the bulge over the disc with an H-band B/D ratio of $69{{\,\rm p…