Search Publications
Discovery of an Ultra-faint Dwarf Galaxy in the Intracluster Field of the Virgo Center: A Fossil of the First Galaxies?
Lee, Myung Gyoon; Jang, In Sung
Ultra-faint dwarf galaxies (UFDs) are newcomers among galaxies, and are the faintest galaxies in the observed universe. To date, they have only been found around the Milky Way Galaxy and M31 in the Local Group. We present the discovery of a UFD in the intracluster field in the core of the Virgo cluster (Virgo UFD1), which is far from any massive g…
Dayglow and auroral emissions of Uranus in H2 FUV bands
Lamy, L.; Roueff, E.; Cessateur, G. +7 more
Following the recent detection of an auroral signal on Uranus (Lamy et al. [2012]. Geophys. Res. Lett. 39, 7105) during HST/STIS observation performed in November 2011, we analyzed the associated HST/STIS FUV spectral images obtained in 2011 and 2012. Our purpose was to extract any possible H2 emission produced in the upper atmosphere o…
Ionization structure of multiple-shell planetary nebulae. I. NGC 2438
Zijlstra, A. A.; Öttl, S.; Kimeswenger, S.
Context. In recent times an increasing number of extended haloes and multiple shells around planetary nebulae have been discovered. These faint extensions to the main nebula trace the mass-loss history of the star, modified by the subsequent evolution of the nebula. Integrated models predict that some haloes may be recombining, and thus are not in…
Listening to galaxies tuning at z ~ 2.5-3.0: The first strikes of the Hubble fork
Cimatti, A.; Halliday, C.; Mignoli, M. +4 more
Aims: We investigate the morphological properties of 494 galaxies selected from the Galaxy Mass Assembly ultra-deep Spectroscopic Survey (GMASS) at z > 1, primarily in their optical rest frame, using Hubble Space Telescope (HST) infrared images, from the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS).
Methods: The …
Magnetic Flux Density in the Heliosphere through Several Solar Cycles
Balogh, A.; Erdős, G.
We studied the magnetic flux density carried by solar wind to various locations in the heliosphere, covering a heliospheric distance range of 0.3-5.4 AU and a heliolatitudinal range from 80° south to 80° north. Distributions of the radial component of the magnetic field, BR , were determined over long intervals from the Helios, ACE, STE…
Cassini nightside observations of the oscillatory motion of Saturn's northern auroral oval
Coates, A. J.; Dougherty, M. K.; Kurth, W. S. +8 more
In recent years we have benefitted greatly from the first in-orbit multi-wavelength images of Saturn's polar atmosphere from the Cassini spacecraft. Specifically, images obtained from the Cassini UltraViolet Imaging Spectrograph (UVIS) provide an excellent view of the planet's auroral emissions, which in turn give an account of the large-scale mag…
Trigonometric Distance and Proper Motion of Iras 20056+3350: A Massive Star-forming Region on the solar Circle
Nakanishi, Hiroyuki; Hayashi, Masahiko; Nakagawa, Akiharu +5 more
We report our measurement of the trigonometric distance and proper motion of IRAS 20056+3350, obtained from the annual parallax of H2O masers. Our distance of D = 4.69+0.65-0.51 kpc, which is 2.8 times larger than the near kinematic distance adopted in the literature, places IRAS 20056+3350 at the leading tip of th…
Herschel Key Program, "Dust, Ice, and Gas In Time" (DIGIT): The Origin of Molecular and Atomic Emission in Low-mass Protostars in Taurus
Lee, Jeong-Eun; Lee, Jinhee; Green, Joel D. +2 more
Six low-mass embedded sources (L1489, L1551-IRS5, TMR1, TMC1-A, L1527, and TMC1) in Taurus have been observed with Herschel-PACS to cover the full spectrum from 50 to 210 µm as part of the Herschel key program, "Dust, Ice, and Gas In Time." The relatively low intensity of the interstellar radiation field surrounding Taurus minimizes contamin…
High speed magnetized flows in the quiet Sun
Ruiz Cobo, B.; Borrero, J. M.; Quintero Noda, C. +1 more
Context. We analyzed spectropolarimetric data recorded with Hinode/SP in quiet-Sun regions located at the disk center. We found single-lobed Stokes V profiles showing highly blue- and red-shifted signals. Oftentimes both types of events appear to be related to each other.
Aims: We aim to set constraints on the nature and physical causes of th…
The Physical Characteristics of the Gas in the Disk of Centaurus A Using the Herschel Space Observatory
Boquien, M.; Roussel, H.; Lebouteiller, V. +12 more
We search for variations in the disk of Centaurus A of the emission from atomic fine structure lines using Herschel PACS and SPIRE spectroscopy. In particular, we observe the [C II](158 µm), [N II](122 and 205 µm), [O I](63 and 145 µm), and [O III](88 µm) lines, which all play an important role in cooling the gas in photo-i…