Search Publications
The ACS Fornax Cluster Survey. IX. The Color-Magnitude Relation of Globular Cluster Systems
Jordán, Andrés; Mieske, Steffen; Infante, Leopoldo +8 more
We investigate the color-magnitude relation for globular clusters (GCs)—the so-called blue tilt—detected in the Advanced Camera for Surveys (ACS) Fornax Cluster Survey and using the combined sample of GCs from the ACS Fornax and Virgo Cluster Surveys. We find a tilt of γ z ≡ d(g - z)/dz = -0.0257 ± 0.0050 for the full GC sample of the …
Statistical Distribution of Size and Lifetime of Bright Points Observed with the New Solar Telescope
Kilcik, Ali; Yurchyshyn, Vasyl; Abramenko, Valentyna +1 more
We present results of 2 hr non-interrupted observations of solar granulation obtained under excellent seeing conditions with the largest aperture ground-based solar telescope—the New Solar Telescope (NST)—of Big Bear Solar Observatory. Observations were performed with adaptive optics correction using a broadband TiO filter in the 705.7 nm spectral…
Long-Term Optical Continuum Color Variability of Nearby Active Galactic Nuclei
Minezaki, Takeo; Yoshii, Yuzuru; Enya, Keigo +8 more
We examine whether the spectral energy distribution of optical continuum emission of active galactic nuclei (AGNs) changes during flux variation, based on accurate and frequent monitoring observations of 11 nearby Seyfert galaxies and QSOs carried out in the B, V, and I bands for seven years by the MAGNUM telescope. The multi-epoch flux data in an…
Spatially-resolved high-resolution spectroscopy of Venus 2. Variations of HDO, OCS, and SO 2 at the cloud tops
Krasnopolsky, Vladimir A.
While CO, HCl, and HF, that were considered in the first part of this work, have distinct absorption lines in high-resolution spectra and were detected four decades ago, the lines of HDO, OCS, and SO 2 are either very weak or blended by the telluric lines and have not been observed previously by ground-based infrared spectroscopy at the…
The Lick AGN Monitoring Project: Alternate Routes to a Broad-line Region Radius
Treu, Tommaso; Filippenko, Alexei V.; Barth, Aaron J. +8 more
It is now possible to estimate black hole (BH) masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central BHs coevolve. Unfortunately, there are many outstanding uncertainties associated with these "virial" mass estimates. One of these comes from using the accretion …
INTEGRAL/IBIS 7-year All-Sky Hard X-ray Survey. I. Image reconstruction
Sunyaev, R.; Krivonos, R.; Tsygankov, S. +5 more
This paper is the first in a series devoted to the hard X-ray whole sky survey performed by the INTEGRAL observatory over seven years. Here we present an improved method for image reconstruction with the IBIS coded mask telescope. The main improvements are related to the suppression of systematic effects that strongly limit sensitivity in the regi…
A Multi-wavelength Study of the Nature of Type 1.8/1.9 Seyfert Galaxies
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +4 more
We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type 1.8 or 1.9. Are these "intermediate" Seyfert types typical Seyfert 1 nuclei with reddened broad-line regions? Or are they objects with intrinsically weak continua and broad emission lines? We compare measurements of the optical reddening of the narrow an…
``TNOs are Cool'': A survey of the trans-Neptunian region. I. Results from the Herschel science demonstration phase (SDP)
Fornasier, S.; Groussin, O.; Gutiérrez, P. J. +32 more
The goal of the Herschel open time key programme “TNOs are Cool!” is to derive the physical and thermal properties for a large sample of Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. We present results for seven targets either observed in PACS point-source, or in mini scan-map mode…
Variation of Saturn's UV aurora with SKR phase
Cecconi, B.; Lamy, L.; Nichols, J. D. +6 more
It is well known that a wide range of kronian magnetospheric phenomena, including the Saturn kilometric radiation (SKR), exhibit oscillations near the planetary rotation period. However, although the SKR is believed to be generated by unstable auroral electrons, no connection has been established to date between diurnal SKR modulations and UV auro…
Flux emergence and coronal eruption
Hood, A. W.; Archontis, V.
Aims: Our aim is to study the photospheric flux distribution of a twisted flux tube that emerges from the solar interior. We also report on the eruption of a new flux rope when the emerging tube rises into a pre-existing magnetic field in the corona.
Methods: To study the evolution, we use 3D numerical simulations by solving the time-dep…