Search Publications
Substellar and low-mass dwarf identification with near-infrared imaging space observatories
Ryan, R.; Holwerda, B. W.; Smit, R. +9 more
Aims: We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope.
Methods: We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the…
Discovery of accretion-driven pulsations in the prolonged low X-ray luminosity state of the Be/X-ray transient GX 304-1
Wijnands, R.; van den Eijnden, J.; Rouco Escorial, A.
We present our Swift monitoring campaign of the slowly rotating neutron star Be/X-ray transient GX 304-1 (spin period of ∼275 s) when the source was not in outburst. We found that between its type I outbursts, the source recurrently exhibits a slowly decaying low-luminosity state (with luminosities of 1034 - 35 erg s-1). This…
Stringent upper limit of CH4 on Mars based on SOFIA/EXES observations
Aoki, S.; Vandaele, A. C.; Sindoni, G. +13 more
Discovery of CH4 in the Martian atmosphere has led to much discussion since it could be a signature of biological and/or geological activities on Mars. However, the presence of CH4 and its temporal and spatial variations are still under discussion because of the large uncertainties embedded in the previous observations. We pe…
Mixed H/He bursts in SAX J1748.9-2021 during the spectral change of its 2015 outburst
Bozzo, E.; Zhang, S.; Kuiper, L. +6 more
SAX J1748.9-2021 is a transiently accreting X-ray millisecond pulsar. It is also known as an X-ray burster source discovered by Beppo-SAX. We analyzed the persistent emission and type-I X-ray burst properties during its 2015 outburst. The source changed from hard to soft state within half day. We modeled the broadband spectra of the persistent emi…
Outstanding X-ray emission from the stellar radio pulsar CU Virginis
Schmitt, J. H. M. M.; Robrade, J.; Oskinova, L. M. +2 more
Context. Among the intermediate-mass magnetic chemically peculiar (MCP) stars, CU Vir is one of the most intriguing objects. Its 100% circularly polarized beams of radio emission sweep the Earth as the star rotates, thereby making this strongly magnetic star the prototype of a class of nondegenerate stellar radio pulsars. While CU Vir is well stud…
Multi-wavelength campaign on NGC 7469. II. Column densities and variability in the X-ray spectrum
Kriss, G. A.; Arav, N.; Bianchi, S. +16 more
We have investigated the ionic column density variability of the ionized outflows associated with NGC 7469, to estimate their location and power. This could allow a better understanding of galactic feedback of AGNs to their host galaxies. Analysis of seven XMM-Newton grating observations from 2015 is reported. We used an individual-ion spectral fi…
Restframe UV-to-optical spectroscopy of APM 08279+5255. BAL classification and black hole mass estimates
Fiore, F.; Vignali, C.; Piconcelli, E. +9 more
We present the analysis of the restframe optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at z = 3.911. The spectroscopic data were taken with the optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between C III] λ1910 and [O III] λλ4959,5007. We have inv…
A study of dust properties in the inner sub-au region of the Herbig Ae star HD 169142 with VLTI/PIONIER
Matter, A.; Weigelt, G.; Ábrahám, P. +3 more
Context. An essential step to understanding protoplanetary evolution is the study of disks that contain gaps or inner holes. The pre-transitional disk around the Herbig star HD 169142 exhibits multi-gap disk structure, differentiated gas and dust distribution, planet candidates, and near-infrared fading in the past decades, which make it a valuabl…
The hot white dwarf in the peculiar binary nucleus of the planetary nebula EGB 6
Rauch, T.; Werner, K.; Kruk, J. W.
EGB 6 is an extended, faint old planetary nebula (PN) with an enigmatic nucleus. The central star (PG 0950+139) is a hot DAOZ-type white dwarf (WD). An unresolved, compact emission knot was discovered to be located 0.''166 away from the WD and it was shown to be centered around a dust-enshrouded low-luminosity star. It was argued that the dust dis…
The AMBRE project: searching for the closest solar siblings
Recio-Blanco, A.; de Laverny, P.; Kordopatis, G. +7 more
Context. Finding solar siblings, that is, stars that formed in the same cluster as the Sun, will yield information about the conditions at the Sun's birthplace. Finding possible solar siblings is difficult since they are spread widely throughout the Galaxy.
Aims: We search for solar sibling candidates in AMBRE, the very large spectra database…