Search Publications
Strengthening the bounds on the r-mode amplitude with X-ray observations of millisecond pulsars
Göğüş, Ersin; Güver, Tolga; Schwenzer, Kai +1 more
R-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the properties of such oscillations, if their surface temperatures can be inferred. We present the results of our invest…
Self-consistent method to extract non-linearities from pulsating star light curves - I. Combination frequencies
Garrido, R.; Pascual-Granado, J.; Lares-Martiz, M.
Stellar pulsation is a common phenomenon and is sustained because of coherent driving mechanisms. When pulsations are driven by heat or convective mechanisms, it is usual to observe combination frequencies in the power spectra of the stellar light-curves. These combination frequencies are not solutions of the perturbed stellar structure equations.…
The MOSDEF survey: an improved Voronoi binning technique on spatially resolved stellar populations at z ∼ 2
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +12 more
We use a sample of 350 star-forming galaxies at 1.25 < z < 2.66 from the Multi-Object Spectrograph For Infra-Red Exploration (MOSFIRE) Deep Evolution Field survey to demonstrate an improved Voronoi binning technique that we use to study the properties of resolved stellar populations in z ~ 2 galaxies. Stellar population and dust maps are con…
Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34
Altamirano, D.; Belloni, T.; Vincentelli, F. M. +4 more
We report the detection of an infrared burst lagging a thermonuclear Type I X-ray burst from the accreting neutron star (NS) 4U 1728-34 (GX 354-0). Observations were performed simultaneously with XMM-Newton (0.7-12 keV), NuSTAR (3-79 keV), and HAWK-I@VLT (2.2 µm). We measure a lag of 4.75 ± 0.5 s between the peaks of the emission in the two …
NGTS-8b and NGTS-9b: two non-inflated hot Jupiters
Jackman, James A. G.; Wheatley, Peter J.; Bayliss, Daniel +36 more
We report the discovery, by the next generation transit survey (NGTS), of two hot Jupiters NGTS-8b and NGTS-9b. These orbit a V = 13.68 K0V star (Teff = 5241 ± 50 K) with a period of 2.49970 d, and a V = 12.80 F8V star (Teff = 6330 ± 130 K) in 4.43527 d, respectively. The transits were independently verified by follow-up phot…
Coupled day-night models of exoplanetary atmospheres
Gandhi, Siddharth; Jermyn, Adam S.
We provide a new framework to model the day side and night side atmospheres of irradiated exoplanets using 1D radiative transfer by incorporating a self-consistent heat flux carried by circulation currents (winds) between the two sides. The advantages of our model are its physical motivation and computational efficiency, which allows for an explor…
Searching for volcanic activity and a mercury-like exosphere of the super-Earth HD3167 b
Guenther, Eike W.; Kislyakova, Kristina G.
HD3167 b is a transiting super-Earth that has a density which is consistent with a rocky composition. The planet is exposed to strong radiation, intense stellar wind, and likely strong tidal forces and induction heating. According to theory, planets that are so close to the star should have an atmosphere like Mercury but much more extended and den…
Probing the atmosphere of HD189733b with the Na I and K I lines
Strassmeier, K. G.; Ilyin, I.; Steffen, M. +12 more
High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high-altitude absorption, e.g. from resonant sodium (Na I) and potassium (K I) lines. We resolve the atmospheric K I absorption on HD189733b with the aim to compar…
The Fundamental Plane of cluster spheroidal galaxies at z ∼ 1.3: evidence for mass-dependent evolution
Marchesini, D.; Annunziatella, M.; Gargiulo, A. +2 more
We present spectroscopic observations obtained at the Large Binocular Telescope in the field of the cluster XLSSJ0223-0436 at z = 1.22. We confirm 12 spheroids cluster members and determine stellar velocity dispersion for 7 of them. We combine these data with those in the literature for clusters RXJ0848+4453 at z = 1.27 (8 galaxies) and XMMJ2235-2…
Streaming classification of variable stars
Protopapas, P.; Zorich, L.; Pichara, K.
In the last years, automatic classification of variable stars has received substantial attention. Using machine learning techniques for this task has proven to be quite useful. Typically, machine learning classifiers used for this task require to have a fixed training set, and the training process is performed offline. Upcoming surveys such as the…