Search Publications
First detections of H13CO+ and HC15N in the disk around HD 97048. Evidence for a cold gas reservoir in the outer disk
Booth, Alice S.; Ilee, John D.; Walsh, Catherine
Observations of different molecular lines in protoplanetary disks provide valuable information on the gas kinematics, as well as constraints on the radial density and temperature structure of the gas. With ALMA we have detected H13CO+ (J = 4-3) and HC15N (J = 4-3) in the HD 97048 protoplanetary disk for the first t…
The HADES RV programme with HARPS-N at TNG. XI. GJ 685 b: a warm super-Earth around an active M dwarf
Rebolo, R.; Ribas, I.; Scandariato, G. +23 more
Context. Small rocky planets seem to be very abundant around low-mass M-type stars. Their actual planetary population is however not yet precisely understood. Currently, several surveys aim to expand the statistics with intensive detection campaigns, both photometric and spectroscopic.
Aims: The HADES program aims to improve the current stati…
Discovery of kilogauss magnetic fields on the nearby white dwarfs WD 1105-340 and WD 2150+591
Bagnulo, S.; Landstreet, J. D.
Magnetic fields are present in roughly 10% of white dwarfs. These fields affect the structure and evolution of such stars, and may provide clues about their earlier evolution history. Particularly important for statistical studies is the collection of high-precision spectropolarimetric observations of (1) complete magnitude-limited samples and (2)…
Carbon and Oxygen Isotopic Ratios. II. Semiregular Variable M Giants
Pilachowski, Catherine A.; Lambert, David L.; Hinkle, Kenneth H. +3 more
Carbon and oxygen isotopic ratios are reported for a sample of 51 SRb- and Lb-type variable asymptotic giant branch stars. Vibration-rotation first- and second-overtone CO lines in 1.5-2.5 µm spectra were measured to derive isotopic ratios for 12C/13C, 16O/17O, and 16O/18O. Co…
The Substructures in the Local Stellar Halo from Gaia and LAMOST
Donlon, Thomas; Du, Cuihua; Li, Hefan +2 more
Based on the second Gaia data release and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope Data, we identified 20,089 halo stars kinematically and chemically. The halo streams in the solar neighborhood could be detected in the space of energy and angular momentum. We reshuffle the velocities of these stars to determi…
Combined geometrical modelling and white-light mass determination of coronal mass ejections
Vourlidas, Angelos; Bothmer, Volker; Pluta, Adam +2 more
Context. We use forward modelling on multi-viewpoint coronagraph observations to estimate the 3-dimensional morphology, initial speed and deprojected masses of Coronal Mass Ejections (CMEs). The CME structure is described via the Graduated Cylindrical Shell (GCS) model, which enables the measurement of CME parameters in a consistent and comparable…
High- and Low-α Disk Stars Separate Dynamically at All Ages
Ness, Melissa K.; Gandhi, Suroor S.
There is a dichotomy in the Milky Way in the [α/Fe]-[Fe/H] plane, in which stars fall into high-α and low-α sequences. The high-α sequence comprises mostly old stars, and the low-α sequence comprises primarily young stars. The origin of this dichotomy is uncertain. To better understand how the high- and low-α stars are affiliated, we examine if th…
Probing Structure in Cold Gas at z ≲ 1 with Gravitationally Lensed Quasar Sight Lines
Ellison, Sara L.; Kulkarni, Varsha P.; Lopez, Sebastian +3 more
Absorption spectroscopy of gravitationally lensed quasars (GLQs) enables study of spatial variations in the interstellar and/or circumgalactic medium of foreground galaxies. We report observations of four GLQs, each with two images separated by 0.″8-3.″0, that show strong absorbers at redshifts 0.4 < z abs < 1.3 in their spectra, …
The visual spectrum of Jupiter's Great Red Spot accurately modeled with aerosols produced by photolyzed ammonia reacting with acetylene
Baines, K. H.; Sromovsky, L. A.; Carlson, R. W. +2 more
We report results incorporating the optical properties of the red-tinted photochemically-generated aerosols of Carlson et al. (2016, Icarus 274, 106-115) in spectral models of Jupiter's Great Red Spot (GRS). This material - created in laboratory GRS simulations from acetylene reacting with photolytic products of ammonia produced by 0.2-µm ra…
From ridges in the velocity distribution to wiggles in the rotation curve
Martinez-Medina, Luis; Pichardo, Barbara; Peimbert, Antonio +1 more
Recently, the Gaiadata release 2 (DR2) showed us the richness in the kinematics of the Milky Way disc. Of particular interest is the presence of ridges covering the stellar velocity distribution, Vϕ-R; as shown by others, it is likely that these ridges are the signature of phase mixing, transient spirals, or the bar. Here, with a Galact…