Search Publications
A closer look at a coronal loop rooted in a sunspot umbra
Peter, H.; Chitta, L. P.; Young, P. R.
Context. Extreme UV (EUV) and X-ray loops in the solar corona connect regions of enhanced magnetic activity, but they are not usually rooted in the dark umbrae of sunspots because the strong magnetic field found there suppresses convection. This means that the Poynting flux of magnetic energy into the upper atmosphere is not significant within the…
A Study of Heliospheric Modulation and Periodicities of Galactic Cosmic Rays During Cycle 24
Moon, Y. -J.; Chowdhury, Partha; Kudela, K.
Galactic cosmic rays (GCRs) are energetic, charged particles coming from outside the solar system. These particles encounter an outward-moving turbulent solar wind with cyclic magnetic-field fluctuations when entering the heliosphere. This causes convection and diffusion in the heliosphere. The GCR counts detected by the ground-based neutron-monit…
Structure and Stability of Magnetic Fields in Solar Active Region 12192 Based on the Nonlinear Force-free Field Modeling
Kusano, K.; Inoue, S.; Hayashi, K.
We analyze a three-dimensional (3D) magnetic structure and its stability in large solar active region (AR) 12192, using the 3D coronal magnetic field constructed under a nonlinear force-free field (NLFFF) approximation. In particular, we focus on the magnetic structure that produced an X3.1-class flare, which is one of the X-class flares observed …
Interactions of the Infrared Bubble N4 with Its Surroundings
Liu, Hong-Li; Liu, Tie; Yuan, Jing-Hua +11 more
The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H II regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble…
Dual Stellar Halos in the Standard Elliptical Galaxy M105 and Formation of Massive Early-type Galaxies
Lee, Myung Gyoon; Jang, In Sung
M105 is a standard elliptical galaxy, located in the Leo I Group. We present photometry of the resolved stars in its inner region at R ≈ 4‧ ≈ 4R eff, obtained from F606W and F814W images in the Hubble Space Telescope archive. We combine this with photometry of the outer region at R ≈ 12‧ ≈ 12R eff from archival imaging data. …
Iron Kα line of boson stars
Cao, Zheng; Bambi, Cosimo; Zhou, Menglei +3 more
The present paper is a sequel to our previous work [1] in which we studied the iron Kα line expected in the reflection spectrum of Kerr black holes with scalar hair. These metrics are solutions of Einstein's gravity minimally coupled to a massive, complex scalar field. They form a continuous bridge between a subset of Kerr black holes and a family…
Are the Dorsa Argentea on Mars eskers?
Conway, Susan J.; Butcher, Frances E. G.; Arnold, Neil S.
The Dorsa Argentea are an extensive assemblage of ridges in the southern high latitudes of Mars. They have previously been interpreted as eskers formed by deposition of sediment in subglacial meltwater conduits, implying a formerly more extensive south polar ice sheet. In this study, we undertake the first large-scale statistical analysis of aspec…
Search for Hyperluminous Infrared Dust-obscured Galaxies Selected with WISE and SDSS
Toba, Y.; Nagao, T.
We aim to search for hyperluminous infrared (IR) galaxies (HyLIRGs) with IR luminosity {L}{{IR}} > 1013 L⊙ by applying the selection method of dust-obscured galaxies (DOGs). They are spatially rare but could correspond to a maximum phase of cosmic star formation (SF) and/or active galactic nucleus (AGN) activity…
Theoretical modelling of the AGN iron line vs. continuum time-lags in the lamp-post geometry
Papadakis, I. E.; Emmanoulopoulos, D.; Dovčiak, M. +4 more
Context. Theoretical modelling of time-lags between variations in the Fe Kα emission and the X-ray continuum might shed light on the physics and geometry of the X-ray emitting region in active galaxies (AGN) and X-ray binaries. We here present the results from a systematic analysis of time-lags between variations in two energy bands (5-7 vs. 2-4 k…
Monsters in the dark: predictions for luminous galaxies in the early Universe from the BLUETIDES simulation
Wilkins, Stephen M.; Nagai, Daisuke; Croft, Rupert +3 more
Using deep Hubble and Spitzer observations Oesch et al. have identified a bright (MUV ≈ -22) star-forming galaxy candidate at z ≈ 11. The presence of GN-z11 implies a number density ∼10-6 Mpc-3, roughly an order of magnitude higher than the expected value based on extrapolations from lower redshift. Using the unpre…