ar X iv : a st ro - p h / 03 05 13 5 v 1 8 M ay 2 00 3 NGC 7538 S - a High - Mass Protostar with a Massive Rotating Disk
نویسندگان
چکیده
We report the detection of a massive rotating disk around the high-mass Class 0 candidate NGC7538 S. The disk is well-resolved with BIMA (θA =3 ′′ . 7) in 3.4 mm continuum and in HCN J=1→0. It is seen nearly edge on and has a size of ∼30,000 AU. A young, powerful outflow perpendicular to the rotating disk is mapped in SiO J=2→1 and HCO J=1→0. The dynamical age of the outflow is ≤ 10,000 yr. The velocity gradient seen in HCN is consistent with Keplerian rotation. Assuming that the gas is gravitationally bound, the mass of the central object is ∼ 40 M⊙. The mass of the continuum “disk” is ≥ 100 M⊙ and has a luminosity of ∼10 L⊙. H CN gives a mass ∼400 M⊙ for the rotating disk, and ∼1000 M⊙ for the extended (20 ) envelope. Our observations confirm that this is an extremely massive protostar in its earliest stages. Subject headings: ISM: clouds – (stars:) circumstellar matter – stars: formation – stars: pre-main sequence – submillimeter
منابع مشابه
ar X iv : a st ro - p h / 99 05 03 1 v 1 5 M ay 1 99 9 Gas Dynamics in the Luminous Merger NGC 6240
We report 0. ′′ 5 × 0. ′′ 9 resolution, interferometric observations of the 1.3 mm CO J=2→1 line in the infrared luminous galactic merger NGC 6240 2. About half of the CO flux is concentrated in a rotating but highly turbulent, thick disk structure centered between the two radio and near-infrared nuclei. A number of gas features connect this ∼500 pc diameter central disk to larger scales.
متن کاملar X iv : a st ro - p h / 03 05 49 9 v 1 2 7 M ay 2 00 3 Discovery of Bright Variable X - ray Sources in NGC 1569 with Chandra
From the analysis of a ∼100 ks Chandra observation of the dwarf starburst galaxy NGC 1569, we have found that the X-ray point sources, CXOU 043048.1+645050 and CXOU 043048.6+645058, showed significant time variability. During this observation, the X-ray flux of CXOU 043048.1+645050 increased by 10 times in only 2 × 10 s. Since the spectrum in its bright phase was fitted with a disk blackbody mo...
متن کاملar X iv : a st ro - p h / 92 05 00 5 v 1 9 M ay 1 99 2 UCSBTH – 92 – 05 April 1992 CHAOTIC DARK MATTER
A very weakly coupled scalar field with mass m and initial vacuum expectation value V will provide enough mass to close the universe provided V ≃ (3 × 10 8 GeV)(100 GeV/m) 1/4. We discuss possible models in which such a field could arise. (a) Electronic address (internet): [email protected].
متن کاملar X iv : a st ro - p h / 05 05 55 5 v 1 2 7 M ay 2 00 5 Pulsars as Tools for Fundamental Physics & Astrophysics
X iv :a st ro -p h/ 05 05 55 5v 1 2 7 M ay 2 00 5 Pulsars as Tools for Fundamental Physics & Astrophysics J. M. Cordes, M. Kramer, T. J. W. Lazio , B. W. Stappers, D. C. Backer, S. Johnston Department of Astronomy and NAIC, Cornell University, Ithaca, NY USA University of Manchester, Jodrell Bank Observatory, Jodrell Bank, UK Naval Research Laboratory, Remote Sensing Division, Washington, DC US...
متن کاملar X iv : a st ro - p h / 03 05 46 5 v 1 2 3 M ay 2 00 3 Sunyaev - Zel ’ dovich cluster surveys using a large beam
Sunyaev Zel’dovich cluster surveys can be used to constrain cosmological parameters. Extracting clusters from the primary anisotropies and the unresolved background from very faint clusters is simple when the telescope beam size is small (∼ 1′), but could be difficult if the beam is larger (∼ 8′). By reference to examples, we show that this is possible by carefully designing the depth of the su...
متن کامل