Search Publications
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…
Infrared study of the star-forming region associated with the UC HII regions G45.07+0.13 and G45.12+0.13
Azatyan, N.; Nikoghosyan, E.; Harutyunian, H. +2 more
Ultra-compact H II (UC HII) regions are an important phase in the formation and early evolution of massive stars and a key component of the interstellar medium (ISM). The main objectives of this work are to study the young stellar population associated with the G45.07+0.13 and G45.12+0.13 UC HII regions, as well as the ISM in which they are embedd…
Broad-band spectral analysis of LMXB 2S 0921-63 with Suzaku
Jain, Chetana; Dutta, Anjan; Sharma, Prince
We present the broad-band spectral analysis of the low-mass X-ray binary 2S 0921-63 by using the Suzaku archival data covering the orbital phase between 0.31 and 1.16 during four close observations. It is the first time that a broad-band spectral analysis of 2S 0921-63 has been done up to 25 keV. The 0.5-10 keV XIS count rate varied between ~1 and…
Stellar population gradients at cosmic noon as a constraint to the evolution of passive galaxies
Andreon, S.; Ditrani, F. R.; Longhetti, M. +1 more
Context. The radial variations of the stellar populations properties within passive galaxies at high redshift contain information about their assembly mechanisms, based on which galaxy formation and evolution scenarios may be distinguished.
Aims: The aim of this work is to give constraints on massive galaxy formation scenarios through one of …