Search Publications
Multi-wavelength Studies of Spectacular Ram-pressure Stripping of a Galaxy. II. Star Formation in the Tail
Makishima, Kazuo; Nakazawa, Kazuhiro; Gu, Liyi +5 more
With multiband photometric data in public archives, we detected four intracluster star-forming regions in the Virgo Cluster. Two of them were at a projected distance of 35 kpc from NGC 4388 and the other two were 66 kpc away. Our new spectroscopic observations revealed that their recessional velocities were comparable to the ram-pressure-stripped …
The Effects of Spatio-temporal Resolution on Deduced Spicule Properties
De Pontieu, Bart; Carlsson, Mats; Pereira, Tiago M. D.
Spicules have been observed on the Sun for more than a century, typically in chromospheric lines such as Hα and Ca II H. Recent work has shown that so-called "type II" spicules may have a role in providing mass to the corona and the solar wind. In chromospheric filtergrams these spicules are not seen to fall back down, and they are shorter lived a…
A Statistical Study of Coronal Active Events in the North Polar Region
Shimojo, Masumi; Watanabe, Tetsuya; Sako, Nobuharu +1 more
In order to study the relationship between characteristics of polar coronal active events and the magnetic environment in which such events take place, we analyze 526 X-ray jets and 1256 transient brightenings in the polar regions and in regions around the equatorial limbs. We calculate the occurrence rates of these polar coronal active events as …
Galaxy Halo Truncation and Giant Arc Surface Brightness Reconstruction in the Cluster MACSJ1206.2-0847
Donahue, Megan; Broadhurst, Tom; Zheng, Wei +32 more
In this work, we analyze the mass distribution of MACSJ1206.2-0847, particularly focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has a significant amount of intracluster light that is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the ov…
A Deep Search for Molecular Gas in Two Massive Lyman Break Galaxies at z = 3 and 4: Vanishing CO-emission Due to Low Metallicity?
Daddi, E.; Elbaz, D.; Morrison, G. +14 more
We present deep IRAM Plateau de Bure Interferometer observations, searching for CO-emission toward two massive, non-lensed Lyman break galaxies at z = 3.216 and 4.058. With one low significance CO detection (3.5σ) and one sensitive upper limit, we find that the CO lines are gsim3-4 times weaker than expected based on the relation between IR and CO…
Uncovering the Deeply Embedded Active Galactic Nucleus Activity in the Nuclear Regions of the Interacting Galaxy Arp 299
Alvarez, C.; Esquej, P.; Colina, L. +14 more
We present mid-infrared (MIR) 8-13 µm spectroscopy of the nuclear regions of the interacting galaxy Arp 299 (IC 694+NGC 3690) obtained with CanariCam (CC) on the 10.4 m Gran Telescopio Canarias (GTC). The high angular resolution (~0.''3-0.''6) of the data allows us to probe nuclear physical scales between 60 and 120 pc, which is a factor of …
X-Ray Grating Observations of Recurrent Nova T Pyxidis during the 2011 Outburst
Ciroi, Stefano; Cracco, Valentina; Page, Kim L. +5 more
The recurrent nova T Pyx was observed with the X-ray gratings of Chandra and XMM-Newton, 210 and 235 days, respectively, after the discovery of the 2011 April 14 outburst. The X-ray spectra show prominent emission lines of C, N, and O, with broadening corresponding to an FWHM of ~2000-3000 km s-1, and line ratios consistent with high-de…
The Tip of the Red Giant Branch Distances to Type Ia Supernova Host Galaxies. II. M66 and M96 in the Leo I Group
Lee, Myung Gyoon; Jang, In Sung
M66 and M96 in the Leo I Group are nearby spiral galaxies hosting Type Ia supernovae (SNe Ia). We estimate the distances to these galaxies from the luminosity of the tip of the red giant branch (TRGB). We obtain VI photometry of resolved stars in these galaxies from F555W and F814W images in the Hubble Space Telescope archive. From the luminosity …
Spectral Signatures of Penumbral Transients
Katsukawa, Y.; Tritschler, A.; Reardon, K.
In this work we investigate the properties of penumbral transients observed in the upper photospheric and chromospheric region above a sunspot penumbra using two-dimensional spectroscopic observations of the Ca II 854.21 nm line with a 5 s cadence. In our 30 minutes of observations, we identify several penumbral-micro jets (PMJs) with cotemporal o…
Discovery of Molecular Hydrogen in White Dwarf Atmospheres
Koester, D.; Zuckerman, B.; Xu, S. +2 more
With the Cosmic Origins Spectrograph on board the Hubble Space Telescope, we have detected molecular hydrogen in the atmospheres of three white dwarfs with effective temperatures below 14,000 K, G29-38, GD 133, and GD 31. This discovery provides new independent constraints on the stellar temperature and surface gravity of white dwarfs.