Search Publications
Revealing δ Cephei's Secret Companion and Intriguing Past
Holl, B.; Mowlavi, N.; Roelens, M. +5 more
Classical Cepheid variable stars are crucial calibrators of the cosmic distance scale thanks to a relation between their pulsation periods and luminosities. Their archetype, δ Cephei, is an important calibrator for this relation. In this paper, we show that δ Cephei is a spectroscopic binary based on newly obtained high-precision radial velocities…
ALMA Observations of the Submillimeter Dense Molecular Gas Tracers in the Luminous Type-1 Active Nucleus of NGC 7469
Meier, David S.; Turner, Jean L.; Imanishi, Masatoshi +30 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 1 observations of the central kiloparsec region of the luminous type 1 Seyfert galaxy NGC 7469 with unprecedented high resolution (0.″5 ×0.″4 = 165 × 132 pc) at submillimeter wavelengths. Utilizing the wide bandwidth of ALMA, we simultaneously obtained HCN(4-3), HCO+(4…
The Spatial Clustering of ROSAT All-Sky Survey Active Galactic Nuclei. IV. More Massive Black Holes Reside in More Massive Dark Matter Halos
Coil, Alison L.; Husemann, Bernd; Krumpe, Mirko +3 more
This is the fourth paper in a series that reports on our investigation of the clustering properties of active galactic nuclei (AGNs) identified in the ROSAT All-Sky Survey and Sloan Digital Sky Survey (SDSS). In this paper we investigate the cause of the X-ray luminosity dependence of the clustering of broad-line, luminous AGNs at 0.16\lt z\lt 0.3…
Close encounters of the stellar kind
Bailer-Jones, C. A. L.
Stars which pass close to the Sun can perturb the Oort cloud, injecting comets into the inner solar system where they may collide with the Earth. Using van Leeuwen's re-reduction of the Hipparcos data complemented by the original Hipparcos and Tycho-2 catalogues, along with recent radial velocity surveys, I integrate the orbits of over 50 000 star…
Depth-dependent global properties of a sunspot observed by Hinode using the Solar Optical Telescope/Spectropolarimeter
Lagg, Andreas; Solanki, Sami K.; Tiwari, Sanjiv K. +1 more
Context. For the past two decades, the three-dimensional structure of sunspots has been studied extensively. A recent improvement in the Stokes inversion technique prompts us to revisit the depth-dependent properties of sunspots.
Aims: In the present work, we aim to investigate the global depth-dependent thermal, velocity, and magnetic proper…
Aeolus: A Markov Chain Monte Carlo Code for Mapping Ultracool Atmospheres. An Application on Jupiter and Brown Dwarf HST Light Curves
Schneider, Glenn; Apai, Dániel; Karalidi, Theodora +2 more
Deducing the cloud cover and its temporal evolution from the observed planetary spectra and phase curves can give us major insight into the atmospheric dynamics. In this paper, we present Aeolus, a Markov chain Monte Carlo code that maps the structure of brown dwarf and other ultracool atmospheres. We validated Aeolus on a set of unique Jupiter Hu…
Linking radio and gamma-ray emission in Ap Librae
Hervet, O.; Boisson, C.; Sol, H.
Ap Lib is one of the rare low-synchrotron-peaked blazars detected so far at TeV energies. This type of source is not properly modelled by standard one-zone leptonic synchrotron self-Compton (SSC) emission scenarios. The aim of this paper is to study the relevance of additional components that should naturally occur in an SSC scenario for a better …
Constraints on neutrino mass from cosmic microwave background and large-scale structure
Knox, L.; Pan, Z.
Our tightest upper limit on the sum of neutrino mass eigenvalues Mν comes from cosmological observations that will improve substantially in the near future, enabling a detection. The combination of the baryon acoustic oscillation feature measured from the Dark Energy Spectroscopic Instrument and a Stage-IV Cosmic Microwave Background ex…
Reanalysis of the Near-infrared Extragalactic Background Light Based on the IRTS Observations
Matsumoto, T.; Pyo, J.; Kim, M. G. +1 more
We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 µm, the res…
The Physical Environment of the Massive Star-forming Region W42
Dewangan, L. K.; Ojha, D. K.; Luna, A. +3 more
We present an analysis of multi-wavelength observations from various data sets and Galactic plane surveys to study the star-formation process in the W42 complex. A bipolar appearance of the W42 complex is evident due to the ionizing feedback from the O5-O6 type star in a medium that is highly inhomogeneous. The Very Large Telescope/NACO adaptive-o…