Search Publications
"TNOs are Cool": A survey of the trans-Neptunian region. XV. Physical characteristics of 23 resonant trans-Neptunian and scattered disk objects
Pál, A.; Lellouch, E.; Marton, G. +7 more
The goal of this work is to determine the physical characteristics of resonant, detached and scattered disk objects in the trans-Neptunian region, observed mainly in the framework of the "TNOs are Cool" Herschel open time key programme. Based on thermal emission measurements with the Herschel/PACS and Spitzer/MIPS instruments, we determine size, a…
Lithium in T Coronae Borealis
Strassmeier, K. G.; Munari, U.; Evans, A. +5 more
T Coronae Borealis is a recurrent, symbiotic nova system currently in quiescence between its periodic ≈80 yr cycle of eruptions. Observations during inter-outburst epochs provide an opportunity to study properties of the accretion disk and the M red giant. Here we present new irradiated (blackbody veiling) models, incorporating modern molecular op…
High-resolution Optical Spectroscopic Observations of Comet 21P/Giacobini-Zinner in Its 2018 Apparition
Shinnaka, Yoshiharu; Kawakita, Hideyo; Tajitsu, Akito
Comet 21P/Giacobini-Zinner is a peculiar comet from the viewpoints of the chemical and physical properties of its dust grains. We conduct optical high-resolution spectroscopic observations of the comet. The intensity ratios of forbidden oxygen lines (at 557.7, 630.0, and 636.4 nm) and ortho-to-para abundance ratios (OPRs) of water cations (H2…
Broadband Linear Polarization in the Region of the Open Star Cluster NGC 1817
Pandey, Jeewan C.; Singh, Sadhana
Multiband linear polarimetric observations of 125 stars in the region of the cluster NGC 1817 have been carried out intending to study properties of interstellar dust and grains in that direction. The polarization is found to be wavelength-dependent, being maximum in the V band with an average value of 0.95%. The foreground interstellar dust grain…
Massive molecular gas reservoir around the central AGN in the CARLA J1103 + 3449 cluster at z = 1.44
Markov, Vladan; Noirot, Gaël; Gonzalez, Anthony H. +14 more
Passive early-type galaxies dominate cluster cores at z ≲ 1.5. At higher redshift, cluster core galaxies are observed to have on-going star-formation, which is fueled by cold molecular gas. We measured the molecular gas reservoir of the central region around the radio-loud active galactic nucleus (AGN) in the cluster CARLA J1103 + 3449 at z = 1.44…
Counterparts of Far Eastern Guest Stars: Novae, supernovae, or something else?
Hoffmann, Susanne M.; Vogt, Nikolaus
Historical observations of transients are crucial for studies of their long-term evolution. This paper forms part of a series of papers in which we develop methods for the analysis of ancient data of transient events and their usability in modern science. Prior research on this subject by other authors has focused on looking for historical superno…
Effects of Solar Activity on Taylor Scale and Correlation Scale in Solar Wind Magnetic Fluctuations
Zhou, G.; Wan, W.; He, H. -Q.
The correlation scale and the Taylor scale are evaluated for interplanetary magnetic field fluctuations from two-point, single time correlation function using the Advanced Composition Explorer (ACE), Wind, and Cluster spacecraft data during the time period from 2001 to 2017, which covers over an entire solar cycle. The correlation scale and the Ta…
Measuring Star Formation Histories, Distances, and Metallicities with Pixel Color-Magnitude Diagrams. II. Applications to Nearby Elliptical Galaxies
van Dokkum, Pieter; Conroy, Charlie; Cook, B. A.
We present spatially resolved measurements of star formation histories (SFHs), metallicities, and distances in three nearby elliptical galaxies and the bulge of M31 derived using the pixel color-magnitude diagram (pCMD) technique. We compute pCMDs from archival Hubble Space Telescope photometry of M87, M49, NGC 3377, and M31, and we fit the data u…
Predicting the Time of Arrival of Coronal Mass Ejections at Earth From Heliospheric Imaging Observations
Vourlidas, Angelos; Stenborg, Guillermo; Dal Lago, Alisson +3 more
The time of arrival (ToA) of coronal mass ejections (CMEs) at Earth is a key parameter due to the space weather phenomena associated with the CME arrival, such as intense geomagnetic storms. Despite the incremental use of new instrumentation and the development of novel methodologies, ToA estimated errors remain above 10 h on average. Here, we inv…
Solar east-west flow correlations that persist for months at low latitudes are dominated by active region inflows
Gizon, Laurent; Birch, Aaron C.; Duvall, Thomas L. +2 more
Context. Giant-cell convection is believed to be an important component of solar dynamics. For example, it is expected to play a crucial role in maintaining the Sun's differential rotation.
Aims: We reexamine early reports of giant convective cells detected using a correlation analysis of Dopplergrams. We extend this analysis using 19 years o…