Search Publications
What planetary nebulae can tell us about jets in core collapse supernovae
Soker, Noam; Bear, Ealeal
We compare the morphology of the core collapse supernova remnant (CCSNR) W49B with the morphology of many planetary nebulae (PNe), and deduce the orientation of the jets that shaped this CCSNR and estimate their energy. We find morphological features that are shared by some PNe and by the CCSNR W49B. In PNe these features, such as a barrel-shaped …
VALES. II. The physical conditions of interstellar gas in normal star-forming galaxies up to z = 0.2 revealed by ALMA
Ivison, R. J.; van Kampen, E.; Cooray, A. +18 more
We use new Band 3 CO(1-0) observations taken with the Atacama Large Millimeter/submillimeter Array (ALMA) to study the physical conditions in the interstellar gas of a sample of 27 dusty main-sequence star-forming galaxies at 0.03 < z < 0.2 present in the Valparaíso ALMA Line Emission Survey (VALES). The sample is drawn from far-IR bright ga…
New Evidence for Charge-sign-dependent Modulation During the Solar Minimum of 2006 to 2009
Potgieter, M. S.; Vos, E. E.; Munini, R. +1 more
The PAMELA space experiment, in orbit since 2006, has measured cosmic rays (CRs) through the most recent period of minimum solar activity with the magnetic field polarity as A < 0. During this entire time, galactic electrons and protons have been detected down to 70 MV and 400 MV, respectively, and their differential variation in intensity with…
Microlensing Constraints on the Mass of Single Stars from HST Astrometric Measurements
Udalski, A.; Rejkuba, M.; Anderson, J. +13 more
We report on the first results from a large-scale observing campaign aiming to use astrometric microlensing to detect and place limits on the mass of single objects, including stellar remnants. We used the Hubble Space Telescope to monitor stars near the Galactic Center for three years, and we measured the brightness and positions of ∼2 million st…
The dust environment of comet 67P/Churyumov-Gerasimenko: results from Monte Carlo dust tail modelling applied to a large ground-based observation data set
Della Corte, Vincenzo; Lara, Luisa M.; Moreno, Fernando +6 more
We present an extensive data set of ground-based observations and models of the dust environment of comet 67P/Churyumov-Gerasimenko covering a large portion of the orbital arc from about 4.5 au pre-perihelion through 3.0 au post-perihelion, acquired during the current orbit. In addition, we have also applied the model to a dust trail image acquire…
Solar Energetic Particle Events with Protons Above 500 MeV Between 1995 and 2015 Measured with SOHO/EPHIN
Dresing, N.; Heber, B.; Kühl, P. +1 more
The Sun is an effective particle accelerator that produces solar energetic particle (SEP) events, during which particles of up to several GeVs can be observed. These events, when they are observed at Earth with the neutron monitor network, are called ground-level enhancements (GLEs). Although these events with their high-energy component have been…
A New Method for Wide-field Near-IR Imaging with the Hubble Space Telescope
van Dokkum, Pieter G.; Franx, Marijn; Muzzin, Adam +6 more
We present a new technique for wide and shallow observations using the near-infrared channel of Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). Wide-field near-IR surveys with HST are generally inefficient, as guide star acquisitions make it impractical to observe more than one pointing per orbit. This limitation can be circumvente…
Pre-flare coronal dimmings
Ji, H. S.; Zhang, Q. M.; Su, Y. N.
Context. Coronal dimmings are regions of decreased extreme-ultravoilet (EUV) and/or X-ray (originally Skylab, then Yohkoh/SXT) intensities, which are often associated with flares and coronal mass ejections (CMEs). The large-scale impulsive dimmings have been thoroughly observed and investigated. The pre-flare dimmings before the flare impulsive ph…
The 2015 outburst of the accretion-powered pulsar IGR J00291+5934: INTEGRAL and Swift observations
Stella, L.; Ferrigno, C.; Bozzo, E. +5 more
The pulsar IGR J00291+5934 is the fastest-known accretion-powered X-ray pulsar, discovered during a transient outburst in 2004. In this paper, we report on INTEGRAL and Swift observations during the 2015 outburst, which lasts for 25 d. The source has not been observed in outburst since 2008, suggesting that the long-term accretion rate has decreas…
Dynamical histories of the IC 348 and NGC 1333 star-forming regions in Perseus
Parker, Richard J.; Alves de Oliveira, Catarina
We present analyses of the spatial distributions of stars in the young (1-3 Myr) star-forming regions IC 348 and NGC 1333 in the Perseus giant molecular cloud. We quantify the spatial structure using the Q-parameter and find that both IC 348 and NGC 1333 are smooth and centrally concentrated with Q-parameters of 0.98 and 0.89, respectively. Neithe…