Search Publications
Imaging Observations of the Hydrogen Coma of Comet 67P/Churyumov-Gerasimenko in 2015 September by the PROCYON/LAICA
Combi, Michael R.; Shinnaka, Yoshiharu; Fougere, Nicolas +8 more
The water production rate of a comet is one of the fundamental parameters necessary to understand cometary activity when a comet approaches the Sun within 2.5 au, because water is the most abundant icy material in the cometary nucleus. Wide-field imaging observations of the hydrogen Lyα emission in comet 67P/Churyumov-Gerasimenko were performed by…
IFU spectroscopy of southern planetary nebulae IV: a physical model for IC 418
Ali, A.; Dopita, M. A.; Sutherland, R. S. +2 more
We describe high spectral resolution, high dynamic range integral field spectroscopy of IC 418 covering the spectral range 3300-8950 Å and compare with earlier data. We determine line fluxes, derive chemical abundances, provide a spectrum of the central star and determine the shape of the nebular continuum. Using photoionization models, we derive …
The Evolution of Star formation Activity in Cluster Galaxies over 0.15 < z < 1.5
Stanford, S. A.; Stern, Daniel; Snyder, Gregory F. +3 more
We explore 7.5 billion years of evolution in the star formation activity of massive ({M}\star > {10}10.1 {M}⊙ ) cluster galaxies using a sample of 25 clusters over 0.15< z< 1 from the Cluster Lensing And Supernova survey with Hubble and 11 clusters over 1< z< 1.5 from the IRAC Shallow Cluster Survey.…
PTF11kx: A Type Ia Supernova with Hydrogen Emission Persisting after 3.5 Years
Fox, O. D.; Filippenko, A. V.; Nugent, P. E. +4 more
The optical transient PTF11kx exhibited both the characteristic spectral features of Type Ia supernovae (SNe Ia) and the signature of ejecta interacting with circumstellar material (CSM) containing hydrogen, indicating the presence of a nondegenerate companion. We present an optical spectrum at 1342 days after peak from Keck Observatory, in which …
A three-dimensional modelling of the layered structure of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +53 more
We provide a three-dimensional model of the inner layered structure of comet 67P based on the hypothesis of an extended layering independently wrapping each lobe. A large set of terrace orientations was collected on the latest shape model and then used as a proxy for the local orientation of the surfaces of discontinuity which defines the layers. …
The nature of 50 Palermo Swift-BAT hard X-ray objects through optical spectroscopy
Palazzi, E.; Minniti, D.; Masetti, N. +16 more
We present the nature of 50 hard X-ray emitting objects unveiled through an optical spectroscopy campaign performed at seven telescopes in the northern and southern hemispheres. These objects were detected with the Burst Alert Telescope (BAT) instrument onboard the Swift satellite and listed as of unidentified nature in the 54-month Palermo BAT ca…
B fields in OB stars (BOB): The magnetic triple stellar system HD 164492C in the Trifid nebula
Ilyin, I.; Järvinen, S.; González, J. F. +15 more
HD 164492C is a spectroscopic triple stellar system that has been recently detected to possess a strong magnetic field. We have obtained high-resolution spectroscopic and spectropolarimetric observations over a time span of two years and derived physical, chemical and magnetic properties for this object. The system is formed by an eccentric close …
Measurement of a Cosmographic Distance Ratio with Galaxy and Cosmic Microwave Background Lensing
Madhavacheril, Mathew S.; Miyatake, Hironao; Spergel, David N. +4 more
We measure the gravitational lensing shear signal around dark matter halos hosting constant mass galaxies using light sources at z ∼1 (background galaxies) and at the surface of last scattering at z ∼1100 (the cosmic microwave background). The galaxy shear measurement uses data from the CFHTLenS survey, and the microwave background shear measureme…
AX J1910.7+0917: the slowest X-ray pulsar
Sidoli, L.; Esposito, P.; Israel, G. L. +2 more
Pulsations from the high-mass X-ray binary AX J1910.7+0917 were discovered during Chandra observations performed in 2011. We report here more details on this discovery and discuss the source nature. The period of the X-ray signal is P = 36200 ± 110 s, with a pulsed fraction, PF, of 63 ± 4 per cent. Given the association with a massive B-type compa…
Indication of a massive circumbinary planet orbiting the low-mass X-ray binary MXB 1658-298
Paul, Biswajit; Jain, Chetana; Dutta, Anjan +2 more
We present an X-ray timing analysis of the transient X-ray binary MXB 1658-298, using data obtained from the RXTE and XMM-Newton observatories. We have made 27 new mid-eclipse time measurements from observations made during the two outbursts of the source. These new measurements have been combined with the previously known values to study long-ter…