scholarly journals Erratum: Year 1 of the ZTF high-cadence Galactic plane survey: strategy, goals, and early results on new single-mode hot subdwarf B-star pulsators

2021 ◽  
Vol 508 (1) ◽  
pp. 560-560
Author(s):  
Thomas Kupfer ◽  
Thomas A Prince ◽  
Jan van Roestel ◽  
Eric C Bellm ◽  
Lars Bildsten ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Single Mode ◽  
Early Results ◽  
Survey Strategy ◽  
High Cadence

scholarly journals Faraday rotation measures of Northern hemisphere pulsars using CHIME/Pulsar

2020 ◽  
Vol 496 (3) ◽  
pp. 2836-2848 ◽  
Author(s):  
C Ng ◽  
A Pandhi ◽  
A Naidu ◽  
E Fonseca ◽  
V M Kaspi ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Faraday Rotation ◽  
Large Scale ◽  
Galactic Plane ◽  
High Signal ◽  
First Year ◽  
Systematic Analysis ◽  
Intensity Mapping ◽  
Rotation Measure ◽  
High Cadence

ABSTRACT Using commissioning data from the first year of operation of the Canadian Hydrogen Intensity Mapping Experiment’s (CHIME) Pulsar backend system, we conduct a systematic analysis of the Faraday Rotation Measure (RM) of the Northern hemisphere pulsars detected by CHIME. We present 55 new RMs as well as obtain improved RM uncertainties for 25 further pulsars. CHIME’s low observing frequency and wide bandwidth between 400 and 800 MHz contribute to the precision of our measurements, whereas the high cadence observation provides extremely high signal-to-noise co-added data. Our results represent a significant increase of the pulsar RM census, particularly regarding the Northern hemisphere. These new RMs are for sources that are located in the Galactic plane out to 10 kpc, as well as off the plane to a scale height of ∼16 kpc. This improved knowledge of the Faraday sky will contribute to future Galactic large-scale magnetic structure and ionosphere modelling.

scholarly journals OH as a Probe of The Milky Way's Hidden Gas: First Results from SPLASH

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
J. R. Dawson ◽  
A. J. Walsh ◽  
Keyword(s):  
Ground State ◽  
Galactic Plane ◽  
Thermal Excitation ◽  
Large Area ◽  
Early Results ◽  
First Results ◽  
Area Survey ◽  
Deep Survey ◽  
Maser Sources ◽  
Future Plans

AbstractSPLASH (the Southern Parkes Large-Area Survey in Hydroxyl) is a deep survey of ground-state OH absorption and emission from the Galactic Plane, as well as an unbiased search for OH masers. Key early results include the detection of a rich and complex distribution of diffuse, optically thin OH with strongly non-thermal excitation temperatures, and the detection of numerous new maser sources. The survey aims to use OH as a probe of CO-dark H2 ISM Galactic scales, with future plans including comprehensive comparisons with CO and Hi, as well as non-LTE excitation modelling of the four ground-state lines.

Ultraviolet Observations of Halo Clouds

1989 ◽  
Vol 120 ◽  
pp. 408-415 ◽  
Author(s):  
Laura Danly ◽  
Chris Blades
Keyword(s):  
Optical Absorption ◽  
Milky Way ◽  
Galactic Plane ◽  
Galactic Rotation ◽  
Considerable Effort ◽  
Refractory Elements ◽  
Early Results ◽  
Absorption Studies ◽  
Ultraviolet Observations ◽  
Halo Gas

Since the earliest optical absorption line studies of Munch and Zirin (1961) identified clouds of gas located at large distances from the galactic plane, considerable effort has gone into trying to understand the origin and nature of Milky Way halo gas. Subsequent high resolution optical absorption studies (Albert 1981; Blades et al 1989) have expanded on the early results, demonstrating clearly that (1) halo clouds are more likely to have velocities outside the range allowed by galactic rotation and (2) halo clouds show smaller depletion of refractory elements compared to their disk counterparts (i.e. the Spitzer-Routley effect).

scholarly journals MALT90: The Millimetre Astronomy Legacy Team 90 GHz Survey

2013 ◽  
Vol 30 ◽  
Author(s):  
J. M. Jackson ◽  
J. M. Rathborne ◽  
J. B. Foster ◽  
J. S. Whitaker ◽  
P. Sanhueza ◽  
...  
Keyword(s):  
Galactic Plane ◽  
High Mass ◽  
Mass Star ◽  
Frequency Range ◽  
Reduction Procedure ◽  
Star Forming ◽  
Photodissociation Regions ◽  
Survey Strategy ◽  
Physical And Chemical ◽  
Excellent Resource

AbstractThe Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey aims to characterise the physical and chemical evolution of high-mass star-forming clumps. Exploiting the unique broad frequency range and on-the-fly mapping capabilities of the Australia Telescope National Facility Mopra 22 m single-dish telescope1, MALT90 has obtained 3′ × 3′ maps towards ~2 000 dense molecular clumps identified in the ATLASGAL 870 μm Galactic plane survey. The clumps were selected to host the early stages of high-mass star formation and to span the complete range in their evolutionary states (from prestellar, to protostellar, and on to $\mathrm{H\,{\scriptstyle {II}}}$ regions and photodissociation regions). Because MALT90 mapped 16 lines simultaneously with excellent spatial (38 arcsec) and spectral (0.11 km s−1) resolution, the data reveal a wealth of information about the clumps’ morphologies, chemistry, and kinematics. In this paper we outline the survey strategy, observing mode, data reduction procedure, and highlight some early science results. All MALT90 raw and processed data products are available to the community. With its unprecedented large sample of clumps, MALT90 is the largest survey of its type ever conducted and an excellent resource for identifying interesting candidates for high-resolution studies with ALMA.

scholarly journals The Fleming Survey: High-cadence Survey for Variable Stars in the Northern Galactic Plane

2021 ◽  
Vol 5 (10) ◽  
pp. 245
Author(s):  
Aleks Scholz ◽  
Ben Warwick ◽  
Thomas van Aalten
Keyword(s):  
Galactic Plane ◽  
Variable Stars ◽  
High Cadence

scholarly journals Preparing to Discover the Unknown with Rubin LSST: Time Domain

2021 ◽  
Vol 258 (1) ◽  
pp. 2
Author(s):  
Xiaolong Li ◽  
Fabio Ragosta ◽  
William I. Clarkson ◽  
Federica B. Bianco
Keyword(s):  
Time Domain ◽  
Milky Way ◽  
Galactic Plane ◽  
Variable Stars ◽  
Magellanic Clouds ◽  
Proper Motions ◽  
Local Volume ◽  
Time Gap ◽  
Survey Strategy ◽  
Stellar Density

Abstract Perhaps the most exciting promise of the Rubin Observatory Legacy Survey of Space and Time (LSST) is its capability to discover phenomena never before seen or predicted: true astrophysical novelties; but the ability of LSST to make these discoveries will depend on the survey strategy. Evaluating candidate strategies for true novelties is a challenge both practically and conceptually. Unlike traditional astrophysical tracers like supernovae or exoplanets, for anomalous objects, the template signal is by definition unknown. We approach this problem by assessing survey completeness in a phase space defined by object color and flux (and their evolution), and considering the volume explored by integrating metrics within this space with the observation depth, survey footprint, and stellar density. With these metrics, we explore recent simulations of the Rubin LSST observing strategy across the entire observed spatial footprint and in specific Local Volume regions: the Galactic Plane and Magellanic Clouds. Under our metrics, observing strategies with greater diversity of exposures and time gaps tend to be more sensitive to genuinely new transients, particularly over time-gap ranges left relatively unexplored by previous surveys. To assist the community, we have made all of the tools developed publicly available. While here we focus on transients, an extension of the scheme to include proper motions and the detection of associations or populations of interest will be communicated in Paper II of this series. This paper was written with the support of the Vera C. Rubin LSST Transients and Variable Stars and Stars, Milky Way, Local Volume Science Collaborations.

scholarly journals Identifying blue large-amplitude pulsators in the Galactic plane using Gaia DR2: a case study

2018 ◽  
Vol 620 ◽  
pp. L9 ◽  
Author(s):  
G. Ramsay
Keyword(s):  
Large Amplitude ◽  
Galactic Plane ◽  
Absolute Magnitude ◽  
High Amplitude ◽  
Variable Stars ◽  
Wide Field ◽  
New Class ◽  
Moderate Resolution ◽  
High Cadence

Blue large-amplitude pulsators (BLAPs) are blue stars emitting high-amplitude (> 0.2 mag) pulsations on a timescale of a few tens of minutes. Recently discovered using OGLE data, they form a new class of variable star and have inspired a number of investigations searching for the origin of their pulsations. This short study presents the Gaia DR2 data for ten BLAPs for which parallax measurements are available. We have dereddened their colours using Gaia DR2 data from the stars in their immediate field and find that six show absolute magnitude and intrinsic colour consistent with expectations, whilst four stars have a less certain classification. This work highlights the extra information that Gaia DR2 data can provide to help classify those variable stars for which moderate-resolution optical spectra are not currently available. We also show how Gaia DR2 can make searches for BLAPs in wide-field high-cadence surveys more systematic and robust.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

Southern Hemisphere Seti Survey: Five Years of Project Meta II

1997 ◽  
Vol 161 ◽  
pp. 611-621
Author(s):  
Guillermo A. Lemarchand ◽  
Fernando R. Colomb ◽  
E. Eduardo Hurrell ◽  
Juan Carlos Olalde
Keyword(s):  
Southern Hemisphere ◽  
Scattering Theory ◽  
Galactic Plane ◽  
Narrow Band ◽  
Neutral Hydrogen ◽  
Sky Survey ◽  
Inertial Frames ◽  
Interstellar Scattering ◽  
Extraterrestrial Origin ◽  
Spectral Channels

AbstractProject META II, a full sky survey for artificial narrow-band signals, has been conducted from one of the two 30-m radiotelescopes of the Instituto Argentino de Radioastronomía (IAR). The search was performed near the 1420 Mhz line of neutral hydrogen, using a 8.4 million channels Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earths rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 2 × 1013spectral channels analyzed, 29 extra-statistical narrow-band events were found, exceeding the average threshold of 1.7 × 10−23Wm−2. The strongest signals that survive culling for terrestrial interference lie in or near the galactic plane. A description of the project META II observing scheme and results is made as well as the possible interpretation of the results using the Cordes-Lazio-Sagan model based in interstellar scattering theory.

Clinical Update: Assessing Maximum Medical Improvement in Carpal Tunnel Syndrome

2003 ◽  
Vol 8 (4) ◽  
pp. 4-5
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Proper Time ◽  
Carpal Tunnel Release ◽  
Hand Function ◽  
Factors Affecting ◽  
Early Results ◽  
Medical Evaluation ◽  
Nerve Recovery ◽  
Tunnel Syndrome

Abstract Permanent impairment cannot be assessed until the patient is at maximum medical improvement (MMI), but the proper time to test following carpal tunnel release often is not clear. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) states: “Factors affecting nerve recovery in compression lesions include nerve fiber pathology, level of injury, duration of injury, and status of end organs,” but age is not prognostic. The AMA Guides clarifies: “High axonotmesis lesions may take 1 to 2 years for maximum recovery, whereas even lesions at the wrist may take 6 to 9 months for maximal recovery of nerve function.” The authors review 3 studies that followed patients’ long-term recovery of hand function after open carpal tunnel release surgery and found that estimates of MMI ranged from 25 weeks to 24 months (for “significant improvement”) to 18 to 24 months. The authors suggest that if the early results of surgery suggest a patient's improvement in the activities of daily living (ADL) and an examination shows few or no symptoms, the result can be assessed early. If major symptoms and ADL problems persist, the examiner should wait at least 6 to 12 months, until symptoms appear to stop improving. A patient with carpal tunnel syndrome who declines a release can be rated for impairment, and, as appropriate, the physician may wish to make a written note of this in the medical evaluation report.

Sign in / Sign up

Export Citation Format

Share Document