Rocket-borne Telescope Research Articles

High-resolution extreme ultraviolet spectroscopy of G191-B2B: structure of the stellar photosphere and the surrounding interstellar medium

We have continued our detailed analysis of the high-resolution (R = 4000) spectroscopic observation of the DA white dwarf G191-B2B, obtained by the Joint Astrophysical Plasma-dynamic Experiment (J-PEX) normal incidence sounding rocket-borne telescope, comparing the observed data with theoretical predictions for both homogeneous and stratified atmosphere structures. We find that the former models give the best agreement over the narrow waveband covered by J-PEX, in conflict with what is expected from previous studies of the lower resolution but broader wavelength coverage Extreme Ultraviolet Explorer spectra. We discuss the possible limitations of the atomic data and our understanding of the stellar atmospheres that might give rise to this inconsistency. In our earlier study, we obtained an unusually high ionization fraction for the ionized He II present along the line of sight to the star. In the present paper, we obtain a better fit when we assume, as suggested by Space Telescope Imaging Spectrograph results, that this He II resides in two separate components. When one of these is assigned to the local interstellar cloud, the implied He ionization fraction is consistent with measurements along other lines of sight. However, the resolving power and signal-to-noise available from the instrument configuration used in this first successful J-PEX flight are not sufficient to clearly identity and prove the existence of the two components.

The Pleiades Reflection Nebula. I. Ultraviolet, Optical, and Far‐Infrared Imaging Photometry

We present new wide-field optical and ultraviolet images of the Pleiades reflection nebula that allow a more thorough evaluation of the dust scattering than any prior data set. Vacuum-UV images were taken at 1650 and 2200 A during the first flight of the Wide-Field Imaging Survey Polarimeter (WISP), a sounding rocket-borne telescope. WISP captured the brighter parts of the nebula at both wavelengths, with 3 σ sensitivities of 22.5 and 23.4 UV mag arcsec-2, respectively. The 50 × 17 WISP field was also mapped at 4400 A with a mosaic of 40 Burrell Schmidt CCD frames using a broadband BJ filter. The Schmidt mosaic shows extensive and intricate nebulosity down to a 5 σ sensitivity limit of 27.6 B mag arcsec-2, including features undetected by photographic surveys. We explore the intensity and color behavior of the nebula in our UV and optical images and far-infrared IRAS data. We find that the photometric structure near bright stars is more complex than previous studies have implied, but general trends are still apparent. The color gradients around the stars are caused by phase function effects rather than internal reddening. The greater concentration of scattered light versus thermal emission indicates that most of the observed scattering is from foreground dust. A somewhat greater concentration of UV versus optical light suggests grain scattering is more forward-directed at shorter wavelengths. The UV nebula is much fainter than expected from the stellar photometry and interstellar reddening. Explaining this UV faintness requires either more reddening than is measured or significant alterations to current dust property estimates.

A Search for a Near-Infrared Halo around NGC 4565

We present a near-infrared (3.5-5 micron) search for the integrated emission from low-mass stars and/or brown dwarfs in the halo of the nearby edge-on spiral galaxy NGC 4565. The observation was made with a liquid-helium-cooled rocket-borne telescope using a 256 x 256 InSb array with a pixel scale of 17. Images of NGC 4565 were successfully obtained with sensitivity near the natural background limit. Our search reveals no evidence of a faint halo around the galaxy, in contrast with the previous reports of a halo around NGC 5907. The lower limit of the mass-to-light ratio for the halo of NGC 4565 is 260 (2 delta) in solar units at 3.5-5 microns. This implies that hydrogen-burning stars do not contribute significantly to the mass of the dark halo in NGC 4565.

A rocket-borne observation of the far-infrared sky at high Galactic latitude

view Abstract Citations (28) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Rocket-borne Observation of the Far-Infrared Sky at High Galactic Latitude Kawada, M. ; Bock, J. J. ; Hristov, V. V. ; Lange, A. E. ; Matsuhara, H. ; Matsumoto, T. ; Matsuura, S. ; Mauskopf, P. D. ; Richards, P. L. ; Tanaka, M. Abstract We have measured the surface brightness of the far-infrared sky at lambda = 134, 154, and 186 micrometers at high Galactic latitude using a liquid-He-cooled, rocket-borne telescope. The telescope scanned over a 5 deg x 20 deg region which includes infrared cirrus, high-latitude molecular clouds, the starburst galaxy M82, and the H I Hole in Ursa Major, a region with uniquely low H I column density. The measured brightness at 134, 154, and 186 micrometers is well correlated with the 100 micrometers brightness measured by IRAS and, in regions excluding molecular clouds, with H I column density. The spectrum of the component correlated with H I is well fitted by a gray-body spectrum with a temperature of 16.4 (+2.3/-1.8) K, assuming an emissivity proportional to lambda-2. Assuming a constant far-infrared dust emissivity per hydrogen nucleus, the ratio of the H2 column density to the velocity-integrated CO intensity in the high-latitude molecular cloud is NH2/Wco = (1.6 +/- 0.3) x 1020/sq cm/(K km/s). The residual brightness after subtracting the emission correlated with H I column density is lambda Ilambda(154 micrometers) = (1.4 +/- 0.6) x 10-12 W/sq cm/sr, yielding an upper limit to the far-infrared extragalactic background radiation of lambda Ilambda(154 micrometers) is less than 2.6 x 10-12 W/sq cm/sr. Publication: The Astrophysical Journal Pub Date: April 1994 DOI: 10.1086/187317 Bibcode: 1994ApJ...425L..89K Keywords: Far Infrared Radiation; Galactic Structure; Infrared Astronomy; Milky Way Galaxy; Rocket-Borne Instruments; Sky Brightness; Telescopes; Cosmic Dust; Extraterrestrial Radiation; Infrared Cirrus (Astronomy); Interstellar Extinction; Interstellar Matter; Molecular Clouds; Starburst Galaxies; Astronomy; ISM: CLOUDS; ISM: DUST; EXTINCTION; ISM: GENERAL full text sources ADS | data products SIMBAD (1)

Far-ultraviolet MAMA detector imagery and emission-line CCD imagery of NGC 6240

An image of the luminous infrared galaxy NGC 6240 at 1480 A was obtained using a multianode microchannel array (MAMA) detector with a rocket-borne telescope. At distances greater than 12 arcsec from the nucleus, the measured ultraviolet luminosity implies intensive star formation activity equal to 2-3 times that of a spiral galaxy such as M83. Optical images in the H-beta and forbidden O III 5007 A emission lines reveal a region of high excitation east of the nucleus between the centers of disks 1 and 2 as described by Bland-Hawthorn et al.

Neutral oxygen and sulfur densities in the Io torus

Ultraviolet spectra (1150-1750 A) of the Io torus, obtained using a rocket-borne telescope and spectrometer in May 1981, show emissions of neutral sulfur and neutral oxygen, as well as ionic emissions of S II, S III, and S IV. The emissions are observed almost 180 deg from the location of the satellite Io and imply the existence of an extended neutral atomic cloud associated with the torus. In the present work, neutral densities and ion mixing ratios are derived by modeling the observations using torus electron temperature and density profiles proportional to those at the time of the Voyager 1 encounter. The model includes the effects of photoexcitation, which can be considerable if the neutral cloud is large enough. At the time of the observation, substantial densities of neutral oxygen and neutral sulfur are found in regions of the torus far from Io. These lower limits on the neutral densities are compared to theoretical models of the neutral source, and the ion mixing ratios are compared to IUE observations of the torus obtained over a period of 5 yr. Arguments that tend to rule out Europa as the source of the neutral emission are also presented.

Images in the rocket ultraviolet - The stellar population in the central bulge of M31

Imagery of the bulge of M31 obtained with a rocket-borne telescope in two broad bands centered at 1460 A and 2380 A is discussed. The UV spatial profiles over a region about 200 arcsec wide are identical with those at visible wavelengths. The absence of detectable point sources indicates that main-sequence stars hotter than B0 V are not present in the bulge. It is suggested that the far-UV flux in old stellar populations originates in post-AGB stars. The UV flux from such stars is extremely sensitive to age and the physics of their previous mass loss.

Images in the rocket ultraviolet - Photometry of M101

view Abstract Citations (26) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Images in the rocket ultraviolet : photometry of M 101. Hill, J. K. ; Bohlin, R. C. ; Stecher, T. P. Abstract Three ultraviolet images of the Sc I galaxy M101 (NGC 5457) were obtained by a rocket-borne telescope, using a microchannel plate image intensifier coupled to IIa-O film, giving an effective wavelength of 2250 Å, a bandpass of 970 Å, and about 10arcsec resolution over an 80arcmin field. Extreme Population I dominates in the UV in the form of OB/H II complexes. The 57 OB/H II sources measured here account for half the UV flux of the galaxy. Large-scale spiral structure was investigated using azimuthal and radial profiles. A comparison with optical results shows that the colors of the disk and spiral arm components do not vary significantly with radius, and that the arm-to-disk ratio is a factor ≡3 higher in the UV than in the visible. Publication: The Astrophysical Journal Pub Date: February 1984 DOI: 10.1086/161724 Bibcode: 1984ApJ...277..542H Keywords: Image Intensifiers; Rocket-Borne Instruments; Spiral Galaxies; Ultraviolet Astronomy; Ultraviolet Photometry; Astronomical Photography; Bandpass Filters; Hydrogen Clouds; Nebulae; Stellar Evolution; Astronomy full text sources ADS | data products SIMBAD (182) NED (3)

Images in the rocket ultraviolet - The starburst in the nucleus of M83

view Abstract Citations (52) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Images in the rocket ultraviolet : the starburst in the nucleus of M 83. Bohlin, R. C. ; Cornett, R. H. ; Hill, J. K. ; Smith, A. M. ; Stecher, T. P. Abstract Ultraviolet images of the SAB(s)c I-II galaxy M83 (NGC 5236) obtained with a rocketborne telescope in broad bandpasses centered at 1540 A and 2360 A show a bright resolved nuclear source which accounts for approximately 20 percent of the flux of the galaxy in both bandpasses. Low-resolution International Ultraviolet Explorer spectra of this source reveal an energy distribution similar to that of the starburst nucleus of NGC 7714. Strong blueshifted absorption lines can be interpreted as evidence for a nuclear wind powered by supernovae. Observations from UV, X-ray, optical, and far-infrared bandpasses are consistent with a starburst approximately one-sixth as strong as that in M82. A scaling of the M82 models of Rieke et al. (1980) predicts that the nucleus of M83 contains 10 to the 6th - 3 x 10 to the 7th solar masses in young stars and has a supernova rate of approximately 0.01 per yr. Publication: The Astrophysical Journal Pub Date: November 1983 DOI: 10.1086/184149 Bibcode: 1983ApJ...274L..53B Keywords: Astronomical Spectroscopy; Galactic Nuclei; Spaceborne Astronomy; Spiral Galaxies; Starburst Galaxies; Ultraviolet Astronomy; Iue; Rocket-Borne Instruments; Spaceborne Telescopes; Stellar Radiation; Supernovae; Astrophysics full text sources ADS | data products SIMBAD (3) NED (2) MAST (1) INES (1)

Ultraviolet images of M101 - Observations of dust and inferences on the metallicity

Since extreme Population I dominates three rocketborne telescope UV images of the Sc I galaxy NGC 5457, the delineation of the spiral structure is sharper than that of ground photographs. The UV pictures, in which the H II regions appear as reflection nebulae and illumine the nearby dust, reveal faint arms which, although correlated with the 21 cm H I radiograph, are only marginally detectable on deep visual photographs. The surface brightness of the arms is explainable in terms of UV light scattering off dust from hot stars and bright H II regions, in which case the dust would have extinction properties and a dust-to-gas ratio similar to that in the solar neighborhood and would in addition suggest that the NGC 5457 outer arm metal content is similar to that of the galaxy.

Long-slit spectroscopy in the rocket ultraviolet of the Orion Nebula

The study deals with the extensive nebulosity in the Trapezium region of Orion. An entrance slit was placed at the focal plane of rocketborne telescope, creating a long-slit spectrograph with a wavelength resolution of 22 A FWHM and a spatial resolution of 14 in. along the slit. Data reduction is outlined, the structure of the Orion Nebula is discussed, and radiative transfer considerations are presented.

Observations of NGC 7662 from 1300 to 2850 Å

An ultraviolet spectrum of NGC 7662 was obtained with a rocket-borne telescope in a 130 s exposure using a microchannel plate detector and film. In addition to the three strong ultraviolet lines of C III], C IV, and He II seen previously in NGC 7027, a new strong line of [Ne IV] at 2440 Å and a prominent continuum were measured in NGC 7662. The observed fluxes are given for both the lines and the continuum on an absolute basis, with a typical accuracy of about 25 percent. The absolute calibration is based primarily on in-flight observations of the stars α Lyr and α And, which have been well measured in the ultraviolet. This calibration is confirmed by laboratory data and by photoelectric observations from the ANS satellite.

(Abstract) Observation of Lyman-alpha Emission in 3C 273 with a Rocket-Borne Telescope

(Abstract) Observation of Lyman-alpha Emission in 3C 273 with a Rocket-Borne Telescope

Ultraviolet spectrum of quasi–stellar object 3C273

The first direct observation of the ultraviolet spectrum of a quasi-stellar object (QSO) has been made with a rocket-borne telescope. The emission line spectrum of 3C273 is similar to the spectra of high-redshift QSOs, but no absorption is observed. The results provide important new constraints on theoretical models of QSOs, place a severe limit on the density of neutral hydrogen in the intergalactic medium, and suggest a cosmological origin for much of the absorption seen in high-redshift QSOs. Comparision of the ultraviolet spectrophotometry of low- and high-redshift QSOs suggests that the universe is closed, with qo ∼ 1.

The rocket-ultraviolet spectrum of the planetary nebula NGC 7027

An ultraviolet spectrum of NGC 7027, obtained with a rocket-borne telescope, is analyzed. Absolute values are presented for the observed fluxes, and upper limits are given for the strongest predicted lines that were not observed. The results are corrected for interstellar extinction using the observed and calculated line ratios between H-beta and the hydrogenic recombination line of He II at 1640 A. The corrected C IV resonance line at 1549 A is found to be in good agreement with the intensity calculated from models, but the intercombination line of C III at 1909 A is found to be too bright by a factor of 10. This discrepancy is reduced to a factor of 4 by taking dielectric recombination into account and is eliminated by using the solar carbon abundance, which implies attenuation in the C IV line. It is shown that no appreciable number of absorbing grains can exist in the C IV-producing region of the nebula since the optical depth is of the order of 10,000 at the line center.

A discussion on infared astronomy - Near infrared night sky background

We have carried out near infrared observations on wide fields of the sky, using both a rocket-borne telescope and ground-based equipment. The rocket observations covered the spectral range of 1 to 8 μm. The ground-based observations were carried out in a narrow spectral region around 1.085 μm. The rocket observations give increased sensitivity over a previous flight carried out by one of us in collaboration with D. P. McNutt, K. Shivanandan and B. J. Zajac of the U.S. Naval Research Laboratory. We observe a general signal which would not have been detected in our previous flight. This new signal appears to be genuine, but because of a number of difficulties, mainly associated with vent gases, we prefer not to trust these signals until we have been able to carry out a confirming flight. We will, in the present paper, use the observed fluxes as an upper limit to the near infrared radiation incident on the top of the atmosphere.

Rocket-Borne Liquid Helium Cooled Telescope

We describe a rocket-borne telescope in which all components in or near the detector's field of view are cooled to liquid helium temperature. The system uses ir detectors to make photometric observations of the night sky in the 5-mu to ~1.6 mm spectral range. A description of the detectors and their calibration is given. On 29 February 1968, the telescope was successfully flown to an altitude of 170 km on an Aerobee 150 sounding rocket.