Search Publications
Missions
Journals
Publication Years
Hubble Tarantula Treasury Project V. The Star Cluster Hodge 301: The Old Face of 30 Doradus
Panagia, N.; Larsen, S.; Lennon, D. J. +10 more
Based on color-magnitude diagrams (CMDs) from the Hubble Space Telescope Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation history of Hodge 301, the oldest star cluster in the Tarantula Nebula. The HTTP photometry extends faint enough to reach, for the first time, the cluster pre-main sequence (PMS) turn-on, where the …
On the Progenitors of Local Group Novae. II. The Red Giant Nova Rate of M31
Shafter, A. W.; Bode, M. F.; Darnley, M. J. +1 more
In our preceding paper, Liverpool Telescope data of M31 novae in eruption were used to facilitate a search for their progenitor systems within archival Hubble Space Telescope data, with the aim of detecting systems with red giant secondaries (RG-novae) or luminous accretion disks. From an input catalog of 38 spectroscopically confirmed novae with …
Changing physical conditions in star-forming galaxies between redshifts 0 < z < 4: [O III]/H β evolution
Bowler, R. A. A.; Cullen, F.; McLure, R. J. +3 more
We investigate the redshift evolution of the [O III]/H β nebular emission line ratio for a sample of galaxies spanning the redshift range 0 < z < 4. We compare the observed evolution to a set of theoretical models which account for the independent evolution of chemical abundance, ionization parameter and interstellar medium (ISM) pressure in…
Evidence for large-scale subsurface convection in the Sun
Woodard, M. F.
A helioseismic statistical waveform analysis of subsurface flow was performed on two 720-day time series of SOHO/Michelson Doppler Imager medium-l spherical-harmonic coefficients. The time series coincide with epochs of high and low solar activity. Time-dependent coupling-strength coefficients b^t_s(n,l) of modes of the same radial order n and deg…
Fe-K Line Time Variability and Ni Abundance of Distant Reflectors in Seyfert Galaxies
Fukazawa, Yasushi; Ohno, Masanori; Noda, Hirofumi +3 more
We have performed systematic studies of narrow Fe-K line (6.4 keV) flux variability and Ni-K line intensity for Seyfert galaxies, using Suzaku and XMM-Newton archival data. Significant Fe-K line variability of several tens of percent was detected for a pair of observations separated by 1000-2000 days (Cen A, IC 4329 A, NGC 3516, and NGC 4151) and …
Compressible turbulence with slow-mode waves observed in the bursty bulk flow of plasma sheet
Dunlop, M.; Cao, Jinbin; Fu, Huishan +2 more
In this paper, we report the evidence of compressible turbulence with slow-mode waves in a bursty bulk flow of plasma sheet. This compressible turbulence is characterized by a multiscale (1-60 s) anticorrelation between plasma density and magnetic field strength. Besides, the magnetic compressibility spectrum stays nearly constant at all the measu…
The Globular Cluster System of the Coma cD Galaxy NGC 4874 from Hubble Space Telescope ACS and WFC3/IR Imaging
Chies-Santos, Ana L.; Peng, Eric W.; Blakeslee, John P. +4 more
We present new Hubble Space Telescope (HST) optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed with the HST Advanced Camera for Surveys in the F475W (g 475) and F814W (I 814) passbands and with the Wide…
The Intrinsic Abundance Ratio and X-factor of CO Isotopologues in L 1551 Shielded from FUV Photodissociation
Lai, Shih-Ping; Lin, Sheng-Jun; Nakamura, Fumitaka +10 more
We investigate the intrinsic abundance ratio of 13CO to C18O and the X-factor in L 1551 using the Nobeyama Radio Observatory (NRO) 45 m telescope. L 1551 is chosen because it is relatively isolated in the Taurus molecular cloud shielded from FUV photons, providing an ideal environment for studying the target properties. Our o…
All-sky census of Galactic high-latitude molecular intermediate-velocity clouds
Kerp, J.; Winkel, B.; Lenz, D. +1 more
Context. The H I halo clouds of the Milky Way, and in particular the intermediate-velocity clouds (IVCs), are thought to be connected to Galactic fountain processes. Observations of fountain clouds are important for understanding the role of matter recycling and accretion onto the Galactic disk and subsequent star formation.
Aims: Here, we qu…
Dynamical analysis of the complex radio structure in 3C 293: clues on a rapid jet realignment in X-shaped radio galaxies
Stawarz, Ł.; Weżgowiec, M.; Jamrozy, M. +1 more
Context. Radio galaxies classified as X-shaped/winged, are characterised by two pairs of extended and misaligned lobes, which suggest a rapid realignment of the jet axis, for which a potential cause (including binary supermassive black holes, a black hole merger, or a Lense-Thirring precession) is still under debate.
Aims: Here we analyse the…