Engineering topics

Huchra, J.

Publications and source records attributed to Huchra, J..

22 records · Page 2

NASA NTRS1981

The UV variability of the Seyfert 1: Galaxies 3 Zw 2 and Markarian 509

The two galaxies differ markedly in their radio properties. III Zw 2 is a strong source with a highly variable compact component while MK 509 is a very weak source. Both galaxies show significant variations in X-rays and MK 509 has shown variations at optical wavelengths as well. Simultaneous observations were made in the ultraviolet, optical and infrared in order to examine three fundamental aspects of the origin of the continuum emission: are these thermal and nonthermal components; how large is the emitting region; and does the UV flux originate in the same region responsible for the optical, IR, radio and/or X-ray continuum emission?

Huchra, J.↗

NASA NTRS1980

A distance scale from the infrared magnitude/H I velocity-width relation. III - The expansion rate outside the local supercluster

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Aaronson, M.↗

NASA NTRS1980

HEAO 1 identification of the X-ray emitting poor cluster of galaxies, AWM 7

The X-ray source 2A 0251 + 413 is identified with the AWM 7 group of galaxies. The source is extended, with a FWHM of roughly 9 arcmin if an isothermal sphere profile is assumed. The spectrum is best fitted by thermal bremsstrahlung at 4.0 + or - 0.5 keV, with a significant Fe line emission of equivalent width 0.63 keV centered at 6.6 keV. This temperature is consistent with a measured dispersion velocity of 600 km/s of the central galaxies.

Schwartz, D. A.↗

NASA NTRS1971

Comments on the instability strip for halo population variables

RR Lyrae stars instability strip for halo population variables, presenting linear nonadiabatic approximate pulsation calculations with emphasis on blue edges location in H-R diagram

Huchra, J.↗