Neutral Hydrogen Observations of Eight Globular Clusters

Knapp, G. R.; Rose, William K.; Kerr, F. J.

doi:10.1086/152550

Cited by 21 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Faulkner et al (1991) detected neutral hydrogen (H i ) at 21 cm in NGC 2808 and inferred the presence of M gas ∼ 200 M ⊙ , but other attempts to detect H i have so far resulted in upper limits of only a few M ⊙ (e.g. Knapp, Rose & Kerr 1973; Smith et al 1990) – down to as little as ∼0.3 M ⊙ in the most sensitive searches performed at Arecibo (Birkinshaw, Ho & Baud 1983; H i detected near M56 is probably associated with intervening material). Ionized gas. Hot stars such as blue horizontal branch stars or post‐AGB stars produce a radiation field with T rad > 10 000 K, which might ionize the ICM.…”

Section: Introductionmentioning

confidence: 99%

Stellar mass loss and the intracluster medium in Galactic globular clusters: a deep radio survey for H i and OH

Loon

Stanimirović

Evans

et al. 2006

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present the results of a survey, the deepest to date, for H i emission at 21 cm and OH emission at 18 cm (lines at 1612, 1665, 1667 and 1720 MHz) in the direction towards the Galactic globular clusters M15, M2, NGC 6934, NGC 7006 and Pal 13. The aim is to measure the amount of hydrogen in the intracluster medium, and to find OH masers in the circumstellar envelopes of globular cluster red giants. We present a tentative detection of 0.3 M⊙ of neutral hydrogen in M15 and possible detections of neutral hydrogen in M2 and Pal 13. We derive upper limits to the neutral hydrogen content of NGC 6934 and 7006. No OH emission is detected. We also present deep H i data of the northern tip of the Magellanic Stream behind Pal 13.

show abstract

Section: Introductionmentioning

confidence: 99%

Stellar mass loss and the intracluster medium in Galactic globular clusters: a deep radio survey for H i and OH

Loon

Stanimirović

Evans

et al. 2006

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Gas shed from the outer layers of evolving stars ought to accumulate in cluster gravitational potential wells in amounts rather larger than the limits set by early H I surveys (Knapp et al 1973). The discrepancy has widened through the intervening years of non-detections down to levels as low as 0.1-20 A/q for many globulars.…”

Section: The First Neutral Hydrogen In a Globular Clustermentioning

confidence: 92%

Astrophysics in 1991

Trimble¹

1992

PASP

View full text Add to dashboard Cite

ABSTRACT. Science, notoriously, progresses amoeba-like, thrusting out pseudopods in unpredictable directions and dragging the rest of the body after or, occasionally, retreating in disorder. This review attempts to shine a narrow and not unprejudiced beam of light on areas of astrophysics where the author believes that something interesting happened in 1991. Length scales range from the kilometers of comets to the gigaparsecs of cosmology, and time scales from milliseconds upward. Eight selfcontained sections discuss the surface of Venus, late activity in Comet Halley, convective overshoot, blue stragglers, new examples and kinds of X-ray binaries and recycled pulsars, hard X and y rays from the galactic-center region, microlensing, and biased cold dark matter. The last two sections contain very short descriptions, with references, of a number of items that did not fit into the main sections but seemed a shame to leave out.

show abstract

“…Under the assumption of emission formed in an extended circumstellar envelope, the observed emission profiles can be obtained both for accretion on the star and for loss of matter. Indications of neither interstellar hydrogen (Knapp et al 1973) nor dust (the results of the IRAS survey analyzed by Knapp et al 1995) were found in globular clusters, thus the hypothesis of wind outflow of matter, with subsequent loss of this matter from the cluster as a whole, seems natural. The difference between the Hα emission of K 413 and the classical P Cygni profile can be due to a thinner circumstellar envelope and a lower mass loss rate.…”

Section: The Spectral Features Of K 413mentioning

confidence: 98%

K 413, a star near the AGB in the globular cluster M 12

Клочкова

Samus

2001

A&A

View full text Add to dashboard Cite

Abstract. CCD spectra obtained with the echelle spectrometer of the 6-meter telescope were used to determine, by the model atmospheres method, the fundamental parameters (T eff = 4800 K, log g = 0. The spectrum of K 413 shows, for the Hα line, an variable absorption and emission profile. From its high luminosity and chemical abundance anomalies, we can suppose that K 413 is in an evolutionary stage after the AGB. In the spectrum, we find absorption details that can be identified with diffuse interstellar bands displaced by 16 km s −1 to longer wavelengths relative to the star's velocity.

show abstract

Neutral Hydrogen Observations of Eight Globular Clusters

Cited by 21 publications

References 0 publications

Stellar mass loss and the intracluster medium in Galactic globular clusters: a deep radio survey for H i and OH

Stellar mass loss and the intracluster medium in Galactic globular clusters: a deep radio survey for H i and OH

Astrophysics in 1991

K 413, a star near the AGB in the globular cluster M 12

Contact Info

Product

Resources

About