Engineering topics

Hughes, S. M.

Publications and source records attributed to Hughes, S. M..

9 records

DOE OSTI2020

The CLAS12 Forward Tagger

This document presents the technical layout and the performance of the CLAS12 Forward Tagger (FT). The FT, composed of an electromagnetic calorimeter based on PbWO$_4$ crystals (FT-Cal), a scintillation hodoscope (FT-Hodo), and several layers of Micromegas trackers (FT-Trk), has been designed to detect electrons and photons scattered at polar angles from 2$^\circ$ to 5$^\circ$ and to meet the physics goals of the hadron spectroscopy program and other experiments running with the CLAS12 spectrometer in Hall B.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

NASA NTRS1998

The HST Key Project on the Extragalactic Distance Scale XX. The Discovery of Cepheids in the Virgo Cluster Galaxy NGC 4548

This is one of the galaxies being observed as part of the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale which aims to determine the Hubble Constant to 10% accuracy.

cepheid variable stars berred spiral galaxy NGC 45↗

NASA NTRS1998

The Extragalactic Distance Scale Key Project. XVI. Cepheid Variables in an Inner Field of M101

We report on the identification of 255 candidate variable stars in a field located some 1.7 from the center of the late-type spiral galaxy M101 = NGC 5457, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope.

indididual galaxies (M101) distances stars Cepheid↗

NASA NTRS1998

The HST Key Project on the Extragalactic Distance Scale. XV. Implications of a Cepheid Distance to the Fornax Cluster

Using the Hubble Space Telescope (HST) thirty-seven long-period Cepheid variables have been discoverd in the Fornax Cluster spiral galaxy NGC 1365.

extragalactic distance scale Cepheid distance Forn↗

NASA NTRS1998

A Cepheid Distance to the Fornax Cluster and the Local Expansion Rate of the Universe

The determination of an accurate value of the Hubble constant requires the measurement of accurate galaxy distances and velocities. Both the Virgo and Fornax clusters of galaxies are close enough to be studied in considerable detail.

Hubble↗

NASA NTRS1998

The HST Key Project on the Extragalactic Distance Scale

We report the detection of Cepheids and a new distance to the spiral galaxy NGC 2541, based on data obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST).

Cepheids spiral galaxy Hubble Space Telescope Extr↗

NASA NTRS1996

The Extragalactic Distance Scale Key Project VIII. The Discovery of Cepheids and a New Distance to NGC 3621 Using the Hubble Space Telescope

We report on the discovery of Cepheids in the field spiral galaxy NGC3621, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 3621 is one of 18 galaxies observed as part of the HST Key Project on the Extragalctic Distance Scale, which aims to measure the Hubble Constant to 10 percent accuracy.

galaxies NGC 3621 stars cepheids Hubble constant↗

NASA NTRS1996

Teh Extragalctic Distance Scale Key Project VII. The Discovery of Cepheids in the Leo I Group Galaxy NGC 3351 Using the Hubble Space Telescope

We report on the discovery and properties of Cepheid variable stars in the barred spiral galaxy NGC 3351 which is a member of the LeoI group of galaxies.

Hubble stars star clusters Cepheid stars galaxies↗

NASA NTRS1994

Distance to the Virgo Cluster Galaxy M100 from Hubble Space Telescope Observations of Cepheids

Accurate distances to galaxies are critical to determining the present expansion rate of the Universe or Hubble Constant (H(sub 0)). An important step in resolving the current uncertainty in H(sub 0) is the measurement of the distance to the Virgo cluster of galaxies. New observations using the Hubble Space Telescope yield a distance of 17.1 +/- 1.8 Mpc to the Virgo cluster galaxy M100. This distance leads to a value of H(sub 0) = 17 km/sec/Mpc. A comparable value of H(sub 0) is also derived from the Coma cluster using independent estimates of its distance ratio relative to the Virgo cluster.

cluster expansion rate↗