Search Publications
The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables
Sarajedini, Ata; Kyeong, Jaemann; Yang, Soung-Chul +2 more
We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys on board the Hu…
Origin of the ionized wind in MWC 349A
Martín-Pintado, J.; Planesas, P.; Thum, C. +2 more
The UC-HII region of MWC 349A is the prototype of an ionized wind driven by a massive star surrounded by a disk. Recent high angular resolution observations of the millimeter recombination lines have shown that the disk rotates with a Keplerian law in its outer parts. However, the kinematics of innermost regions in the UC-HII region of MWC 349A is…
Extended HCN and HCO+ Emission in the Starburst Galaxy M82
Bolatto, A. D.; Galaz, G.; Herrera-Camus, R. +3 more
We mapped 3 mm continuum and line emission from the starburst galaxy M82 using the Combined Array for Research in Millimeter-wave Astronomy. We targeted the HCN, HCO+, HNC, CS, and HC3N lines, but here we focus on the HCN and HCO+ emission. The map covers a field of 1.'2 with an ≈5'' resolution. The HCN and HCO
Collection of Minima of Eclipsing Binaries
Zasche, P.; Svoboda, P.; Uhlar, R. +2 more
We present CCD times of minima for selected eclipsing binaries. Besides our own data as obtained at various observatories, the photometric surveys (ASAS, SuperWASP, etc.) were also used.
The X-ray coronae of the two brightest galaxies in the Coma cluster
Simionescu, A.; Churazov, E.; Fabian, A. C. +4 more
We use deep Chandra X-ray Observatory observations to examine the coronae of the two brightest cluster galaxies in the Coma cluster of galaxies, NGC 4874 and NGC 4889. We find that NGC 4889 hosts a central depression in X-ray surface brightness consistent with a cavity or pair of cavities of radius 0.6 kpc. If the central cavity is associated with…
Detection of l = 4 and l = 5 Modes in 12 Years of Solar VIRGO-SPM Data—Tests on Kepler Observations of 16 Cyg A and B
Silva Aguirre, Victor; Christensen-Dalsgaard, Jørgen; Handberg, Rasmus +2 more
We present the detection of l = 4 and l = 5 modes in power spectra of the Sun, constructed from 12 yr full-disk VIRGO-SPM data sets. A method for enhancing the detectability of these modes in asteroseismic targets is presented and applied to Kepler data of the two solar analogues 16 Cyg A and B. For these targets, we see indications of a signal fr…
The Fast UV Variability of the Active Galactic Nucleus in Fairall 9
Reynolds, Christopher S.; Mushotzky, Richard F.; Lohfink, Anne M. +2 more
We present the results from a new optical/UV/X-ray monitoring campaign of the luminous Seyfert galaxy Fairall 9 using the Swift satellite. Using the UV-Optical Telescope on Swift, we find correlated optical/UV variability on all timescales ranging from the sampling time (4 days) to the length of the campaign (2.5 months). In one noteworthy event, …
Herschel/PACS spectroscopy of trace gases of the stratosphere of Titan
Lara, L. M.; Hartogh, P.; Lellouch, E. +7 more
Aims: We investigate the composition of Titan's stratosphere from new medium-resolution far-infrared observations performed with the full range of Herschel's Photodetector Array Camera and Spectrometer (PACS) (51-220 µm at a resolution λ/Δλ ranging from 950 to 5500 depending on wavelength and grating order).
Methods: Using PACS, we…
Different Periodicities in the Sunspot Area and the Occurrence of Solar Flares and Coronal Mass Ejections in Solar Cycle 23 - 24
Norris, M.; Lawrence, J. K.; Cadavid, A. C. +1 more
In order to investigate the relationship between magnetic-flux emergence, solar flares, and coronal mass ejections (CMEs), we study the periodicity in the time series of these quantities. It has been known that solar flares, sunspot area, and photospheric magnetic flux have a dominant periodicity of about 155 days, which is confined to a part of t…
Constraining the True Nature of an Exotic Binary in the Core of NGC 6624
Pallanca, Cristina; Dalessandro, Emanuele; Ferraro, Francesco R. +4 more
We report on the identification of the optical counterpart to Star1, the exotic object serendipitously discovered by Deutsch et al. in the core of the Galactic globular cluster NGC 6624. Star1 has been classified by Deutsch et al. as either a quiescent cataclysmic variable or a low-mass X-ray binary. Deutsch et al. proposed StarA as a possible opt…