Search Publications
Chemical Abundances of Eight Highly-extincted Milky Way Planetary Nebulae
Dinerstein, Harriet L.; Zeimann, Greg; Sterling, N. C. +1 more
Low- and intermediate-mass (0.8 M ⊙ < M < 8 M ⊙) stars that evolve into planetary nebulae (PNe) play an important role in tracing and driving Galactic chemical evolution. Spectroscopy of PNe enables access to both the initial composition of their progenitor stars and products of their internal nucleosynthesis, but deter…
Analysis of Gaia radial-velocity standards: stability and new substellar companion candidates
Gosset, E.; Damerdji, Y.; Morel, T. +4 more
Our main aim is to test the non-variability of the radial velocity (RV) of a sample of 2351 standard stars used for wavelength calibration of the Radial Velocity Spectrometer (RVS) instrument onboard Gaia. In this paper, we present the spectroscopic analysis of these stars with the determination of their physical parameters by matching observed an…
Improving INTEGRAL/SPI data analysis of GRBs
Greiner, Jochen; Siegert, Thomas; Biltzinger, Björn +1 more
The spectrometer on the international gamma-ray astrophysics laboratory (INTEGRAL/SPI) is a coded mask instrument observing since 2002 in the keV to MeV energy range, which covers the peak of the νFν spectrum of most gamma-ray bursts (GRBs). Since its launch in 2008, the gamma-ray burst monitor (GBM) on board the Fermi satellite has been the prima…
The Electric Field outward of Saturn's Main Rings
Krupp, N.; Roussos, E.; Paranicas, C. +5 more
Cassini data are consistent with a global electric field in Saturn's magnetosphere that points approximately antisunward. The inner radial extent of this field was initially established using Saturn orbit insertion data but measurements of ultrarelativistic electrons from that pass cast some doubt on whether the electric field reaches all the way …
Understanding the evolution of radiation damage on the Gaia CCDs after 72 months at L2
Seabroke, George; Ahmed, Saad; Holland, Andrew +5 more
The European Space Agency's Gaia spacecraft has been operating in L2 ever since its launch in December 2013 with a payload that includes 106 scientific charge-coupled devices (CCDs). Due to the predicted radiation environment at the pre-flight testing stage in addition to the high level of accuracy demanded by the science objectives, the non-ioniz…
Scaling properties of magnetic field fluctuations in the quiet Sun
Giannattasio, F.; Berrilli, F.; Consolini, G. +1 more
Context. The study of the dynamic properties of small-scale magnetic fields in the quiet photosphere is important for several reasons: (i) it allows us to characterise the dynamic regime of the magnetic field and points out some aspects that play a key role in turbulent convection processes; (ii) it provides details of the processes and the spatia…
The past decade of ZERODUR glass-ceramics in space applications
Krieg, Janina; Carré, Antoine; Döhring, Thorsten +4 more
For the past four decades, ZERODUR® glass ceramics has flown on many satellites including the prominent space missions METEOSAT, Hubble Space Telescope, CHANDRA, and LISA pathfinder. Firstly, this unique material is chosen as mirror substrate for high precision optics due to its extreme thermal stability. Its near-zero thermal expansion over a wid…
Orbital Elements of visual binary stars with very short arcs: With application to double stars from the 1829 southern double star catalog of James Dunlop
Letchford, Roderick R.; White, Graeme L.; Brown, Carolyn J.
Binary double stars are those whose binding energies are less than zero. Obtaining binary star orbits from short arcs has been a long-standing problem in astrophysics. A method is presented and tested here, which addresses the problem by using space-based astrometry, photometry, and astrophysical data, together with historic measures, to generate …
Ammonia in the interstellar medium of a starbursting disc at z = 2.6
Ivison, R. J.; Menten, K. M.; Dye, S. +4 more
We report the detection of the ground state rotational emission of ammonia, ortho-NH3 (JK = 10 → 00) in a gravitationally lensed intrinsically hyperluminous star-bursting galaxy at z = 2.6. The integrated line profile is consistent with other molecular and atomic emission lines which have resolved kinema…
Challenging the Disk Instability Model. I. The Case of YZ LMi
Baptista, Raymundo; Schlindwein, Wagner
Observations of YZ LMi show enhanced emission along the stream trajectory beyond impact at the disk rim during outbursts as well as when the quiescent disk is large. We investigated whether these features can be explained in terms of either gas stream overflow or penetration within the frameworks of the disk instability model (DIM) and the mass-tr…