Search Publications
An infrared view of AGN feedback in a type-2 quasar: the case of the Teacup galaxy
Villar-Martín, M.; Ramos Almeida, C.; Piqueras López, J. +1 more
We present near-infrared integral field spectroscopy data obtained with Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) of 'the Teacup galaxy'. The nuclear K-band (1.95-2.45 µm) spectrum of this radio-quiet type-2 quasar reveals a blueshifted broad component of FWHM ∼ 1600-1800 km s-1
Radio Pulse Search and X-Ray Monitoring of SAX J1808.4-3658: What Causes Its Orbital Evolution?
Hessels, Jason W. T.; Wijnands, Rudy; van der Klis, Michiel +6 more
The accreting millisecond X-ray pulsar SAX J1808.4-3658 shows a peculiar orbital evolution that proceeds at a very fast pace. It is important to identify the underlying mechanism responsible for this behavior because it can help to understand how this system evolves and which physical processes (such as mass loss or spin-orbit coupling) are occurr…
Observational Evidence of Magnetic Reconnection for Brightenings and Transition Region Arcades in IRIS Observations
Feng, Li; Zhu, Xiaoshuai; Li, Hui +4 more
By using a new method of forced-field extrapolation, we study the emerging flux region AR11850 observed by the Interface Region Imaging Spectrograph and Solar Dynamical Observatory. Our results suggest that the bright points (BPs) in this emerging region exhibit responses in lines formed from the upper photosphere to the transition region, which h…
Imaging a Central Ionized Component, a Narrow Ring, and the CO Snowline in the Multigapped Disk of HD 169142
Carrasco-González, Carlos; Rodríguez, Luis F.; Macías, Enrique +5 more
We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the millimeter emission of this disk with the highest angular resolution so far (0.″12 × 0.″09, or 14 au × 11 au, at 7 mm). Our 7 and 9 mm images show a narrow ring of emissio…
Constraining the dark energy equation of state using Bayes theorem and the Kullback-Leibler divergence
Hobson, M. P.; Lasenby, A. N.; Hee, S. +2 more
Data-driven model-independent reconstructions of the dark energy equation of state w(z) are presented using Planck 2015 era cosmic microwave background, baryonic acoustic oscillations (BAO), Type Ia supernova (SNIa) and Lyman α (Lyα) data. These reconstructions identify the w(z) behaviour supported by the data and show a bifurcation of the equatio…
Precise surface gravities of δ Scuti stars from asteroseismology
Reese, D. R.; Garrido, R.; Martín-Ruiz, S. +8 more
The work reported here demonstrates that it is possible to accurately determine surface gravities of δ Scuti (δ Sct) stars using the frequency content from high-precision photometry and a measurement of the parallax. Using a sample of 10 eclipsing binary systems with a δ Sct component and the unique δ Sct star discovered with a transiting planet, …
The Interstellar Medium in High-redshift Submillimeter Galaxies as Probed by Infrared Spectroscopy*
Smith, Matthew W. L.; van der Werf, Paul; Valtchanov, Ivan +21 more
Submillimeter galaxies (SMGs) at z≳ 1 are luminous in the far-infrared, and have star formation rates, SFR, of hundreds to thousands of solar masses per year. However, it is unclear whether they are true analogs of local ULIRGs or whether the mode of their star formation is more similar to that in local disk galaxies. We target these questions by …
Exposure age of Saturn's A and B rings, and the Cassini Division as suggested by their non-icy material content
Nicholson, P. D.; Janssen, M. A.; Hayes, A. G. +4 more
Saturn's rings are composed primarily of water ice with a small fraction of non-icy constituents that are likely both intrinsic and extrinsic in origin. The intrinsic material is thought to be characteristic of the ring progenitor, while the extrinsic material is derived from the continual stream of hypervelocity impacting micrometeoroids that pol…
First Detection of Prominence Material Embedded within a 2 × 106 K CME Front Streaming away at 100-1500 km s-1 in the Solar Corona
Habbal, Shadia Rifai; Ding, Adalbert
Coronal mass ejections (CMEs) are the largest and most dynamic explosions detected in the million degree solar corona, with speeds reaching up to 3000 km s-1 at Earth’s orbit. Triggered by the eruption of prominences, in most cases, one of the outstanding questions pertaining to the dynamic CME-prominence system is the fate of the cool …
Computational helioseismology in the frequency domain: acoustic waves in axisymmetric solar models with flows
Gizon, Laurent; Birch, Aaron C.; Fournier, Damien +7 more
Context. Local helioseismology has so far relied on semi-analytical methods to compute the spatial sensitivity of wave travel times to perturbations in the solar interior. These methods are cumbersome and lack flexibility.
Aims: Here we propose a convenient framework for numerically solving the forward problem of time-distance helioseismology…