Search Publications
A quartet of black holes and a missing duo: probing the low end of the MBH-σ relation with the adaptive optics assisted integral-field spectroscopy
Krajnović, Davor; Sarzi, Marc; Cappellari, Michele +8 more
We present mass estimates of supermassive black holes in six nearby fast rotating early-type galaxies (NGC 4339, NGC 4434, NGC 4474, NGC 4551, NGC 4578, and NGC 4762) with effective stellar velocity dispersion around 100 km s-1. We use near-infrared laser-guide adaptive optics observations with the GEMINI/NIFS to derive stellar kinemati…
Anatomy of Eddington-like inversion methods in the context of dark matter searches
Lacroix, Thomas; Stref, Martin; Lavalle, Julien
Irrespective of the dark matter (DM) candidate, several potentially observable signatures derive from the velocity distribution of DM in halos, in particular in the Milky Way (MW) halo. Examples include direct searches for weakly-interacting massive particles (WIMPs), p-wave suppressed or Sommerfeld-enhanced annihilation signals, microlensing even…
Pre-eruptive Magnetic Reconnection within a Multi-flux-rope System in the Solar Corona
Wang, Haimin; Wang, Yuming; Shen, Chenglong +2 more
The solar corona is frequently disrupted by coronal mass ejections (CMEs), whose core structure is believed to be a flux rope made of helical magnetic field. This has become a “standard” picture; though, it remains elusive how the flux rope forms and evolves toward eruption. While one-third of the ejecta passing through spacecraft demonstrate a fl…
Hitomi observation of radio galaxy NGC 1275: The first X-ray microcalorimeter spectroscopy of Fe-Kα line emission from an active galactic nucleus
Done, Chris; Safi-Harb, Samar; Hamaguchi, Kenji +191 more
The origin of the narrow Fe-Kα fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In 2016 February-March, we performed the first X-ray microcalorimeter spectroscopy with the Soft X…
A Subarcsecond ALMA Molecular Line Imaging Survey of the Circumbinary, Protoplanetary Disk Orbiting V4046 Sgr
Kastner, Joel H.; Forveille, T.; Hily-Blant, P. +6 more
We present a suite of Atacama Large Millimeter Array (ALMA) interferometric molecular line and continuum images that elucidate, on linear size scales of ∼30-40 au, the chemical structure of the nearby, evolved, protoplanetary disk orbiting the close binary system V4046 Sgr. The observations were undertaken in the 1.1-1.4 mm wavelength range (ALMA …
On the Factors Determining the Eruptive Character of Solar Flares
Veronig, Astrid M.; Thalmann, Julia K.; Baumgartner, Christian
We investigated how the magnetic field in solar active regions (ARs) controls flare activity, i.e., whether a confined or eruptive flare occurs. We analyzed 44 flares of GOES class M5.0 and larger that occurred during 2011-2015. We used 3D potential magnetic field models to study their location (using the flare distance from the flux-weighted AR c…
First Results from the Herschel and ALMA Spectroscopic Surveys of the SMC: The Relationship between [C II]-bright Gas and CO-bright Gas at Low Metallicity
Warren, Steven R.; Bolatto, Alberto D.; Meixner, Margaret +15 more
The Small Magellanic Cloud (SMC) provides the only laboratory to study the structure of molecular gas at high resolution and low metallicity. We present results from the Herschel Spectroscopic Survey of the SMC (HS3), which mapped the key far-IR cooling lines [C II], [O I], [N II], and [O III] in five star-forming regions, and new ALMA …
Thermal inertia and roughness of the nucleus of comet 67P/Churyumov-Gerasimenko from MIRO and VIRTIS observations
Jorda, L.; Kührt, E.; Mottola, S. +17 more
Aims: Using data from the Rosetta mission to comet 67P/Churyumov-Gerasimenko, we evaluate the physical properties of the surface and subsurface of the nucleus and derive estimates for the thermal inertia (TI) and roughness in several regions on the largest lobe of the nucleus.
Methods: We have developed a thermal model to compute the tem…
Non-thermal X-rays from colliding wind shock acceleration in the massive binary Eta Carinae
Hamaguchi, Kenji; Corcoran, Michael F.; Russell, Christopher M. P. +9 more
Cosmic-ray acceleration has been a long-standing mystery1,2 and, despite more than a century of study, we still do not have a complete census of acceleration mechanisms. The collision of strong stellar winds in massive binary systems creates powerful shocks that have been expected to produce high-energy cosmic rays through Fermi acceler…
Mass models of NGC 6624 without an intermediate-mass black hole
Jonker, Peter G.; Hénault-Brunet, Vincent; Gieles, Mark +4 more
An intermediate-mass black hole (IMBH) was recently reported to reside in the centre of the Galactic globular cluster (GC) NGC 6624, based on timing observations of a millisecond pulsar (MSP) located near the cluster centre in projection. We present dynamical models with multiple mass components of NGC 6624 - without an IMBH - which successfully d…