Search Publications

Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei. III. CRIRES observations of the Circinus galaxy

Marconi, A.; Capetti, A.; Axon, D. J. +2 more

We present new CRIRES spectroscopic observations of the Brγ emission line in the nuclear region of the Circinus galaxy, obtained with the aim of measuring the black hole (BH) mass with the spectroastrometric technique. The Circinus galaxy is an ideal benchmark for the spectroastrometric technique given its proximity and secure BH measurement obtai…

Observations and Models of Slow Solar Wind with Mg^{9 +} Ions in Quiescent Streamers

Abbo, L.; Giordano, S.; Ofman, L.

Quiescent streamers are characterized by a peculiar UV signature as pointed out by the results from the observations of the Ultraviolet and Coronograph Spectrometer (UVCS) on board SOHO: the intensity of heavy-ion emission lines (such as O VI) shows dimmer core relative to the edges. Previous models show that the structure of the heavy-ion streame…

A Search for Helioseismic Signature of Emerging Active Regions

Kholikov, S.

Using SOHO/MDI and GONG observations we present time-distance deep-focusing measurements to examine the deeper layers of the solar convective zone. The constructed travel-time maps show 10 - 15 second perturbations at depths of 40 - 75 Mm around active region locations before their emergence to the solar surface. The majority of the active regions…

The First Circumstellar Disk Imaged in Silhouette at Visible Wavelengths with Adaptive Optics: MagAO Imaging of Orion 218-354

Close, Laird M.; Males, Jared R.; Morzinski, Katie M. +11 more

We present high-resolution adaptive optics (AO) corrected images of the silhouette disk Orion 218-354 taken with Magellan AO (MagAO) and its visible light camera, VisAO, in simultaneous differential imaging mode at Hα. This is the first image of a circumstellar disk seen in silhouette with AO and is among the first visible light AO results in the …

XMM-Newton and Chandra observations of G272.2-3.2. Evidence of stellar ejecta in the central region

Bocchino, F.; Combi, J. A.; Martí, J. +4 more

Aims: We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant G272.2-3.2 in order to obtain important constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant.
Methods: We report on combined XMM-Newton and Chandra ima…

Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies

Orellana, R. B.; Corti, M. A.

Context. An OB association is a gravitationally unbound group of stars. The identification of the members of the association is an important aspect of its study. There are few astrometric membership studies for OB associations, but the combination of these studies with astrophysical techniques becomes a very powerful tool for this type of research…

Erratum: The Herschel PEP/HerMES Luminosity Function - I. Probing the Evolution of PACS selected Galaxies to z ≃ 4

Berta, S.; Magnelli, B.; Nordon, R. +100 more

XMM-Newton/Reflection Grating Spectrometer detection of the missing interstellar O VII Kα absorption line in the spectrum of Cyg X-2

Wang, Q. Daniel; Yao, Yangsen; Cabot, Samuel H. C.

The hot interstellar medium is an important part of the Galactic ecosystem and can be effectively characterized through X-ray absorption line spectroscopy. However, in a study of the hot medium using the accreting neutron star X-ray binary, Cyg X-2, as a background light source, a mystery came about when the putatively strong O VII Kα line was not…

Difference in the Spatial Distribution between H₂O and CO₂ Ices in M 82 Found with AKARI

Oyabu, Shinki; Onaka, Takashi; Yamagishi, Mitsuyoshi +5 more

With AKARI, we obtain the spatially resolved near-infrared (NIR) (2.5-5.0 µm) spectra for the nearby starburst galaxy M 82. These spectra clearly show absorption features due to interstellar ices. Based on the spectra, we created the column density maps of H₂O and CO₂ ices. As a result, we find that the spatial distribu…

The Circumnuclear Star Formation Environment of NGC 6946: Br γ and H₂ Results from Keck Integral Field Spectroscopy

Meier, David S.; Turner, Jean L.; Beck, Sara C. +2 more

We present a three-dimensional data cube of the K-band continuum and the Br γ, H₂ S(0), and S(1) lines within the central 18.''5 × 13.''8 (520 pc × 390 pc) region of NGC 6946. Data were obtained using OSIRIS, a near-infrared Integral Field Spectrograph at Keck Observatory, with Laser Guide Star Adaptive Optics. The 0.''3 resolution allo…