ratio along
the jet and the disappearance of the optical emission after a
characteristic scale length.
The Structure of Optical Stellar Jets: a Phenomenological Analysisg
F. Bacciotti[1], C. Chiuderi[2] and E. Oliva[3]
[1] Observatoire de la Côte d'Azur, B.P. 229, 06304 Nice Cedex 4, France,
internet: bacciott@rossini.obs-nice.fr
[2]Dipartimento di Astronomia e Scienza dello Spazio, Università
di Firenze, Largo E. Fermi 5, I-50125 Firenze, Italy
internet: chiuderi@arcetri.astro.it
[3]Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5,
I-50125 Firenze, Italy
internet: oliva@arcetri.astro.it
In this paper we discuss the possible mechanisms of formation ot the nodular structure of Herbig-Haro jets. The available spectral observations of the linear jet section in the HH 34 and the HH 111 complexes are reviewed, in order to diagnostic the temperature and ionization state of the emitting material in a way as model-independent as possible. The values we find by means of an original although straightforward diagnostic procedure (T ~ 6000 K, x = nH+ / nH ~ 0.1, in both cases), are similar to those empirically determined by Brügel et al. (1981) and Böhm and Solf (1990) for the compact object HH 7.
Our results lead to a value of the momentum rate in these flows comparable to the rates observed in high-speed neutral winds (Lizano et al. 1988), giving support to the view according to which the bright optical jet actually identifies the axial portion of the neutral flow, and marks the location where the matter attains its maximum velocity and an observable amount of ionization. The ionization derived from the observations is likely to be a remnant of the heating and the excitation occurred in the accelerating region, where the wind is probably focused by the passage through a nozzle. The recombination time scale appropriate for the rather low electron densities in the jet is found to be close to the crossing time of the visible portion of the jet.
Combining kinematical and energetic considerations we
show that physical conditions consistent with the
observed jet's emission can be
obtained through ''soft'' compressions of the central portion
of the flow, caused by 'damped' Kelvin-Helmoltz instabilities
generated at the jet-ambient contact discontinuity.
These compressions concentrate in smaller volumes the already
available internal energy that is eventually radiated in
optical and IR lines, unlike the weak shocks that actually
increase the internal energy content by transforming the
bulk kinetic energy into thermal random motions.
A picture of this kind seems capable of resolving the long-standing
problem of conciling the high supersonic velocity of the ionized
material and the low excitation nature of the emission,
and, at the same time, provides a very natural explanation for a
number of observational constraints,
among which the increase of the [SII]/H ratio along
the jet and the disappearance of the optical emission after a
characteristic scale length.
Accepted by Astronomy and Astrophysics
Harold M. Butner[1] and Antonella Natta[2]
[1] Department of Terrestrial Magnetism, Carnegie Institution of Washington,
5241 Broad Branch Road,
N. W., Washington, DC 20015, USA, email: butner@dtm.ciw.edu
[2] Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
This paper examines the nature of deeply embedded sources found in
association with optically visible Herbig Ae/Be stars, such as the
recently discovered 10 µm object LkH 198-IR. The possibility that
such deeply embedded objects, instead of the optical stars, are
responsible for the extended far-infrared emission detected by
the Kuiper Airborne Observatory
is investigated by
using three types of models. The first considers LkH 198-IR to be
a star embedded in a dense cloud and the only
source responsible for the far-infrared emission. The second
set of models replaces the embedded star with
an embedded star+disk system.
The third set of models has both
LkH 198-IR and LkHa 198-OP (the optical star)
as sources of equal luminosity, where
LkH 198-IR is in the center of a dense cloud and
the optical star is at the edge.
We argue, based on these results, that the extended
far-infrared emission is most likely associated
with LkH 198-OP, and, more generally, that the extended far-infrared
emission seen around many Herbig Ae/Be stars is associated
with the known optical star rather than any deeply
embedded companion.
By combining our models with existing sub-millimeter observations, we
suggest that
in the LkH 198 region we are seeing
a roughly spherical
cloud of moderate mass and thickness, characterized by a rather flat density,
which contains LkH 198-OP
and, possibly, LkH 198-IR. The large extinction
toward the latter, revealed by the deep 10 µm absorption feature
seen against it, is best explained as arising
in a thick circumstellar disk.
Accepted by the Astrophysical Journal, to appear in the Feb. 10, 1995 issue.
Physical Properties of Dense Cores: DCO
+
Observations
Harold M. Butner[1,2,3], Elizabeth A. Lada[4,5], and Robert B. Loren[6]
[1] Present Address: Department of Terrestrial Magnetism,
Carnegie Institution of Washington, 5241 Broad Branch Road, N. W.,
Washington, DC 20015, USA email: butner@dtm.ciw.edu
[2] NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035, USA
[3] Department of Astronomy, University of Texas at Austin, Austin,
Tx 78712, USA
[4] Present Address: Astronomy Program, University of Maryland,
College Park, MD 20742
email: lada@astro.umd.edu
[5] Harvard-Smithsonian Center for Astrophysics, MS 42, 60 Garden Street,
Cambridge, MA 02138, USA
[6] Unaffiliated
We conducted a survey for C18O, DCO+, and H¹³CO+
J=1
0 emission in
a sample of low mass cores previously surveyed in CS, NH3, and C3H2.
The DCO+ and H¹³CO+ observations were used to test deuteration
fractionation chemistry models for TMC-1 type clouds.
The [DCO+/HCO+]
fractionation ratio (0.045±0.014)
was found to be in excellent agreement with current models.
In addition, we did
a multiple transition study of DCO+ emission
which revealed the presence of denser
gas (n 
105 cm-3) than most previous molecular line
studies of these cores had found.
The observations also suggested that those cores which are
associated with young stars have slightly higher densities
on average than those cores
which have no associated star.
We also found DCO+ linewidths for the
cores studied are significantly broader than the previously observed
NH3 linewidths. The DCO+ linewidth broadening
does not appear to be entirely an opacity effect.
Instead, the broader linewidth suggests the
presence inside the core of a dense supersonic gas component
not traced by NH3.
Accepted by the Astrophysical Journal, to appear in the Feb. 10, 1995 issue.
Jonathan Ferreira and Guy Pelletier
Laboratoire d'Astrophysique de l'Observatoire de Grenoble
BP 53, 414 rue de la piscine, F-38041 Grenoble cedex 9, France
The production of jets from a Keplerian accretion disk, thread by a bipolar magnetic field, is considered as a successful paradigm for young stellar objects (YSOs) and Radio Loud active galactic nuclei (AGN). However, while the acceleration of the jet is understood, the issue of the expell of a part of the matter from the disk is still an enigma. In this paper, we elucidate the physical process that leads to ejection, exhibit the conditions allowing the steady state launch of jets and expound the properties of these magnetized accretion-ejection structures.
As in a huge Barlow wheel, the magnetic field lines extract all the angular momentum and the mechanical power from the disk, while a turbulent magnetic diffusivity allows the matter to pass through the field lines and thus, to be accreted. Because of the disk differential rotation, the radial current decreases as one goes upwards in the disk atmosphere, leading then to a change of sign of the magnetic torque. From this point on, both angular momentum and energy are transfered back to the matter. Magnetic azimuthal acceleration leads to the increase of the angular velocity which drives an outwards radial velocity, while the magnetic pressure associated to the horizontal field develops a vertical acceleration. Hence, magnetically driven jets can be seen as being both centrifugally and magnetic pressure driven. At the still resistive base of the jet, the magnetic force pushes matter towards the magnetic surfaces. A transition between the resistive disk and the ideal MHD jet is then naturally achieved.
The intrinsic two-dimensionality of the problem arises as a regularity condition that must be satisfied, in order to smoothly break through a slow magnetosonic critical point. We derive the observational signatures of such a disk, as well as the global energy budget and its consequences on the jets, depending on the mass ejection rate. Magnetized accretion disks supply their jets with almost all the available gravitational power, being then weakly dissipative. We discuss the possibility for the disk to be either convective or radiative, in regard to its settlement around a young stellar object, or within an active galactic nuclei. Self-consistent solutions are displayed in the context of AGN and YSOs.
Accepted by A&A
R. A. Gaume,[1,2] W. M. Goss[3], H. R. Dickel[4], T. L. Wilson[5], K. J. Johnston,[1,*]
[1] U.S. Naval Observatory, 3450 Massachusetts Ave., NW, Washington,
DC 20392-5420, USA
[2] Code 7213, Naval Research Lab. Washington, DC ~20375-5351, USA
[3] NRAO, PO Box 0, Socorro, NM ~87801, USA
[4] Astronomy Department, 1002 West Green Street, University of
Illinois, Urbana, IL 61801, USA
[5] Max Planck Institut für Radioastronomie, Postfach 2024,
D-53010 Bonn, Germany
The continuum and the H 66 recombination line emission
toward NGC 7538 IRS1 have been imaged with a spatial resolution of 180
&300 AU respectively. There are several remarkable aspects to the data.
The core of the HII region is composed of numerous emission clumps with
peak brightness temperatures of 
15,000K. Extremely wide line
profiles, 250 km s-1 FWZP, are observed from the core, indicating substantial
mass motions of the ionized gas. The H 66 spectral profiles
exhibit multiple emission peaks. The peaks and shapes of the
H 66 recombination line profiles vary significantly as a function
of position within the core region. The H 66 line-to-continuum
ratios also vary considerably within the core region. A thin strip midway
between the northern and southern core continuum components is the
region of largest electron density. The center of this dense, disk-like
structure most likely delineates the position of the exciting star.
We present a model for NGC 7538 IRS1 that involves a stellar wind outflow and
photoevaporation of nearby clumpy neutral material. This results in a clumpy
continuum appearance and a complicated set of broad and multiple
peaked spectral profiles. Ionized gas escapes the core region in an outflow to
the north and south. Toward the south the outflow is partially limited by
neutral material, producing a southern, spherical continuum component which
exhibits much narrower H 66 line profiles than the core region.
Accepted by Astrophysical Journal, currently scheduled for the Jan 10, 1995 issue
Effect of gas drag on the dynamics of protostellar
clumps in molecular clouds
U. Gorti and H. C. Bhatt
Indian Institute of Astrophysics, Koramangala, Bangalore 560034
India
(e-mail: gorti@iiap.ernet, hcbhatt@iiap.ernet.in)
Molecular clouds are observed to have sub-structure within them and consist of dense condensations or clumps which are surrounded by a less dense inter-clump medium. The inter-clump gas could retard the motion of the clumps in the cloud through a drag force caused by dynamical friction. The effect of such a drag force on the dynamics of protostellar clumps in a molecular cloud has been numerically analysed. Since the forces are mass dependent, the more massive clumps suffer greater drag and settle towards the centre in shorter timescales. This causes a radial segregation with respect to mass of the clumps in the cloud. This segregation induced by dynamical friction is found to be significant for protostellar clumps in interstellar clouds as the timescale involved is much shorter than the typical cloud lifetime or the N-body relaxation time.
The segregation is more pronounced and quicker in denser clouds. Variations in clump mass spectra and density profile of interclump gas have little effect on the dynamics, and do not affect the timescale of segregation in the cloud system very much. There is also some velocity segregation with respect to mass, with the more massive clumps tending to have lower velocities. This is not, however, as pronounced as the spatial segregation. The most massive star-forming clumps are thus expected to be closer to the centre of the parent cloud. Subsequent star formation in these clumps could then explain the mass segregation observed in many young clusters of pre-main sequence stars and YSOs.
Accepted by M.N.R.A.S
Ageing Jets from Low-Mass Stars
J.A. Graham[1], W.P. Chen[2]
[1] Department of Terrestrial Magnetism, Carnegie Institution of Washington,
Washington, DC 20015, USA
[2] Institute of Astronomy, National Central University, Chung-Li, Taiwan, ROC
An extended faint optical jet is associated with the compact emission region
plus faint star known as HH 55. HH 55 is located in the Lupus 2 cloud 2´ SW
of the well studied T Tauri star RU Lupi. The HH 55 jet extends 55" N and
35" S in PA 160°. The HH 55 star is an emission line star of spectral
type M3.5. Its image in the emission lines of H and [S II] is slightly
elongated by 2 - 3" to the S but in continuum light is symmetrical and
pointlike (FWHM = 1.7"). The star and jet have several features in common
with the star and jet known as Sz 102 = Th 28 in the nearby Lupus 3 cloud. We
suggest that these objects are representative of the late evolutionary stage of
the HH jet-outflow phenomenon and point out that such objects may be quite
common although difficult to detect. With LBol ~ 0.005 L
and
log Te ~
3.5, the HH 55 star is close to the main sequence and evolutionary
tracks suggest an age of 3 × 107 years.
Accepted by The Astronomical Journal
A Multitransitional Study of the Cep C Cloud Core
M. H. Heyer[1] and E. F. Ladd[2]
[1] Five College Radio Astronomy Observatory, 619 Lederle Graduate Research
Center, University of Massachusetts, Amherst, MA 01003, USA
(heyer@fcrao1.phast.umass.edu)
[2] Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive,
Honolulu, HI 96822, USA
Strip maps of ¹²CO, ¹³CO, and C18O J=2-1 and J=1-0 emissions from the Cep C dense core have been obtained to determine its density distribution and kinematic properties. Using large velocity gradient models to estimate gas conditions, The H2 volume density ranges between 2500 cm-3 at the core edge to 7000 cm-3 at the central position. Absorption features are found in the ¹²CO lines which are redshifted with respect to the cloud core velocities. Self-absorption is also identified in the profiles of ¹³CO J=2-1 emission but at velocities much closer to those of the central core of the line. Such velocity structure denotes different kinematics and thermal conditions within several layers of material along the line of sight.
Accepted by Ap. J.
Doppler Imaging of the T Tauri Star HDE 283572
Isabelle Joncour, Claude Bertout and Jérôme Bouvier
Laboratoire d'Astrophysique, Observatoire de Grenoble, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
We present Doppler images of the surface temperature
distribution of the rapidly rotating weak-emission line T
Tauri star HDE 283572, as computed from the
FeI 
6400Å,
FeI 6393Å,
CaI 6439Å, and LiI 6707Å
photospheric lines. This analysis reveals the presence of
one large polar structure 1600 K colder than the surrounding
photosphere. We also find a possible rotational modulation
of the H and CaII equivalent line widths that
suggests the presence of large-scale chromospheric
structures above the stellar surface.
Accepted by A&A
Spatially Resolved Submillimeter Continuum Emission Toward L1551 IRS-5
E. F. Ladd[1], G. A. Fuller[2], R. Padman[3], P. C. Myers[4], and Fred C. Adams[5]
[1] Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive,
Honolulu, HI 96822 (ladd@fcrao1.phast.umass.edu)
[2] National Radio Astronomy Observatory, 520 Edgemont Road,
Charlottesville, VA 22903, USA
[3] Mullard Radio Astronomy Observatory, Cavendish Laboratory, Cambridge
CB3 0HE, England
[4] Harvard-Smithsonian Center for Astrophysics, Mail Stop 42,
60 Garden St., Cambridge, MA 02138, USA
[5] Department of Physics, University of Michigan, Ann Arbor, MI
48109, USA
We present high signal-to-noise ratio 16-20" resolution
submillimeter continuum images of the embedded young stellar object
L1551 IRS-5. The images are dominated by a compact source at the
position of IRS-5, which has a deconvolved size of 10 ± 3". Low
level emission extends up to 5000 A. U. from IRS-5 and is distributed
non-axisymetrically. The 1100µm emission is extended in the
north-south direction and elliptical in shape. In contrast, our
730µm map shows emission in a cross-shaped pattern, with arms
extending to the north, south, east, and west of IRS-5. The cross
emission is not an artifact of our observational methods, but intrinsic
to the source distribution. We model the submillimeter continuum
emission at 1100µm and 730µm using three components: an
unresolved point source; a cold (~12 K), massive (~1 M),
smoothly-distributed envelope; and a warm (> 50
K), less massive (< 0.02 M) "cross" centered at the
position of IRS-5. We note that the arms of the cross are well-aligned
with the edges of the CO outflow from IRS-5, and suggest that they may
consist of core material warmed and pushed aside by the
energetically-dominant outflow.
Accepted by Ap. J.
Richard B. Larson
Yale Astronomy Department, New Haven, CT 06520-8101, USA; Internet: larson@astro.yale.edu
In order to study the relation between clustering and binary formation, the analysis by Gomez et al. (1993) of the clustering of young stars in the Taurus region has been extended to smaller separations by using data from recent searches for close companions to these stars. The Taurus young stars are found to exhibit self-similar or fractal clustering on the largest scales, but there is a clear break from self-similarity at a scale of about 0.04 pc which divides the regime of binary and multiple systems on smaller scales from that of true clustering on larger scales. This break provides clear evidence for the existence of an intrinsic scale in the star formation process, and this scale is found to be essentially equal to the Jeans length in typical molecular cloud cores. The associated mass is of the order of one solar mass, supporting the hypothesis that typical stellar masses are determined by the Jeans mass. Both the self-similar clustering of the Taurus stars on the larger scales and the power-law form of the upper stellar IMF may have their origin in hierarchical and perhaps fractal-like cloud structure. The very different distribution of stellar separations that is observed in the regime of binary and multiple systems strongly suggests that these systems are not formed in the same way as the hierarchical clustering, but by a distinct mechanism which is probably the fragmentation of collapsing clumps of about the Jeans size. The evidence suggests that nearly all stars are formed in binary or multiple systems, and that some of these systems are subsequently disrupted by interactions in the denser star-forming environments to produce the observed mixture of single, binary, and multiple stars.
Accepted by Monthly Notices of the R.A.S.
Discovery of a molecular hydrogen jet near IC348
Mark J. McCaughrean[1], John T. Rayner[2], and Hans Zinnecker[3]
[1]Max-Planck-Institut für Astronomie,
Königstuhl 17,
D-69117 Heidelberg, Germany
E-mail: mjm@mpia-hd.mpg.de
[2]Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive,
Honolulu, HI 96822, USA
E-mail: rayner@ifa.hawaii.edu
[3]Institüt für Astronomie und Astrophysik,
Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
E-mail: hans@astro.uni-wuerzburg.de
We present near-infrared images of a newly discovered molecular hydrogen jet (HH211) near the young stellar cluster IC348 in the Perseus dark cloud complex. A wide-field true-colour JHK´ image locates HH211 relative to the embedded source IC348-IR, and a high-resolution image taken in the H2 v=1-0 S(1) line at 2.122µm delineates the shock-excited gas. The jet is very young, with a dynamical age of < 1000 yrs. We suggest that the H2 emission arises in a turbulent sheath around the true jet, leading to an unusual symmetric limb-brightened appearance. This boundary layer is probably where ambient molecular material is being entrained to form a coincident bipolar CO outflow. We discuss possible models for the knots in HH211, including internal working surfaces in an episodic outflow and crossing shocks in a recollimating jet. The exciting source of the jet and outflow was detected at > 350µm, and our observations imply that the exciting source is a young star deeply embedded in a dense NH3 core, perhaps an edge-on circumstellar disk. The HH211 system of jet, molecular outflow, and embedded exciting source is the first discovered through near-infrared imaging.
Accepted by The Astrophysical Journal (Letters)
(A preprint version of this paper may be obtained via anonymous ftp or the World Wide Web. For the former, connect to spitfire.mpia-hd.mpg.de, login as ftp, using your e-mail address as password, cd preprints, and get README for further instructions. Using WWW, connect to http://spitfire.mpia-hd.mpg.de/Preprints.html and follow the relevant links to this paper.)
A simulation of an HH jet in a molecular environment
A. C. Raga[1], S. D. Taylor[1], S. Cabrit[2], and S. Biro [3]
[1] Mathematics Dep., UMIST. P.O. Box 88, Mancheter M60 1QD, UK
[2] Observatoire de Grenoble, B. P. 53X, 38041 Grenoble Cedex,
France
[3] Astronomy Dep. University of Manchester, Manchester M5S 1A1, UK
The heads of some Herbig-Haro (HH) jets have recently been detected in emission lines of molecular species such as H2 and CO. In this paper we present an axisymmetric numerical simulation of an atomic, nonadiabatic jet moving into a molecular environment, from which predictions of intensity maps in atomic/ionic and molecular emission lines can be carried out. While the maps predicted from these models for emission lines of atoms and ions have the expected bow-shaped structure, the maps for H2 lines have a ``hole'' in the stagnation region of the bowshock, where the molecules are dissociated. The morphology predicted for the molecular emission intensity maps is in clear qualitative agreement with recent observational results. We also present predictions of position-velocity diagrams, which will be useful for comparisons with future long-slit spectroscopic observations of HH objects.
Accepted by Astron. J.
Molecular mixing layers in stellar outflows
S. D. Taylor, and A. C. Raga
Mathematics Dep., UMIST, P.O. Box 88, Manchester M60 1QD, UK
Molecular outflows possibly are the result of the interaction between a high velocity jet from a young star and the surrounding molecular environment. This interaction can take place through the formation of a turbulent mixing layer. We present models of a plane mixing layer in the boundary between a high velocity, atomic wind (the stellar jet) and a stationary, molecular environment, which are computed considering a detailed chemical network.
The chemical composition of the mixing layer initially corresponds to the direct mixture of the (atomic) jet and (molecular) environmental material. However, we find that the mixing layer is hot (with temperatures exceeding 104 K), so that the mixing layer quickly becomes ``chemically active'', especially since H2 molecules are only partially dissociated. A number of molecules are either created or survive in the high velocity flow.
The emission from such atomic jet/molecular environment mixing layers is dominated by emission in the rotational and vibrational lines of H2. As a result of the high temperatures (~104 - 105 K) and velocities (ranging from zero to the jet velocity) of these mixing layers, the predicted H2 emission line spectrum has characteristics that are interestingly different.
Accepted by Astron. J.
X-ray Emission from Herbig Ae/Be stars: A ROSAT survey
H. Zinnecker and Th. Preibisch
Institut für Astronomie und Astrophysik der Universität Würzburg, Am Hubland, D-97074 Würzburg, Federal Republic of Germany, Internet: hans@astro.uni-wuerzburg.de, preib@astro.uni-wuerzburg.de
We have observed 14 Herbig Ae/Be stars in X-rays with the ROSAT PSPC (0.1 - 2.4 keV). In addition, we obtained data from the ROSAT archive for 7 Herbig Ae/Be stars. As a result, 11 of the 21 Herbig Ae/Be stars studied here have been detected as X-ray sources, among them AB Aur, HR 5999/6000, and Z CMa. This is surprising, since Ae/Be stars, being predominantly radiative, are unlikely to sustain dynamo magnetic fields and coronal heating. We have investigated possible correlations between the X-ray luminosity and other stellar parameters like LBol, spectral type, stellar rotation and winds. We suspect that the origin of the X-ray emission is likely to be related to the stellar wind, although other explanations (e.g. unresolved T Tauri companions) are also discussed. Some Ae/Be stars are known to be the exciting sources of high-velocity jets, but none of the jets themselves were detected in X-rays. In several cases, the X-ray images revealed a small cluster of sources, presumably lower mass pre-main-sequence objects that surround the more massive Ae/Be stars.
Accepted for Astronomy and Astrophysics
( A preprint of the paper (TeX file and figures as Postscript files)
can be obtained per e-mail from Th. Preibisch)
CO: Twenty-five Years of Millimeter-wave Spectroscopy
A symposium to celebrate the 25th anniversary of the detection of carbon monoxide.
29 May - 2 June 1995 Tucson, Arizona USA
Co-Sponsored by: The National Radio Astronomy Observatory - Tucson The Submillimeter Telescope Observatory
Symposium Objective:
Interstellar carbon monoxide (CO) and several other basic molecules were first detected twenty-five years ago with the 36-foot telescope of the National Radio Astronomy Observatory. These discoveries have profoundly influenced our understanding of several diverse yet interrelated fields, including the phases of the interstellar medium, the initial and final phases of stellar evolution, the chemistry of dense and diffuse interstellar matter and the solar system, the structure of the Milky Way galaxy, and the content and structure of other galaxies. These research areas are among the most fundamental in astrophysics, and the spectroscopic information provided by CO and other molecules serves as the primary tool of investigation. New developments in instrumentation will further increase the power and utility of molecular line spectroscopy. The twenty-fifth anniversary of the detection of CO is a timely opportunity to bring researchers in all these areas together to review progress and discuss future directions. The emphasis of the meeting will be on CO and other molecules as tracers and diagnostics: what we have learned from CO and what remains to be learned
General Topics to be Discussed:
William Latter or Darrel Emerson
NRAO
949 N. Cherry Ave.
Tucson, AZ 85721
USA
(602) 882-8250
(602) 882-7955 (FAX)
symp95@nrao.edu (Internet)
Stellar Jets and Bipolar Outflows
Proceedings of the Sixth International Workshop of the Astronomical Observatory of Capodimonte (OAC 6), held at Capri, Italy, September 18-21, 1991.
Edited by L.Errico, Alberto A Vittone
Astrophysics and Space Science Library 186
The book contains the oral and poster presentations from the Capri meeting. Discussions after the talks are also included. The following are the invited reviews presented:
S. Cabrit: Molecular Outflows from Young Stellar Objects
R. Mundt: Observational Properties of Jets from Young Stars
F. Paresce: Observation of Circumstellar Environments with the Hubble Space Telescope
J. Solf: Bipolar Outflows and Jets from Central Stars of Planetary Nebulae
A.M. Cherepashchuk: Parameters of SS 433 as a Massive Binary System
T.P. Ray: Interpreting Jets from Young Stars
A. Königl: The Origin of Energetic Outflows in Young Stellar Objects
M. Camenzind: Magnetic Fields, Disk Winds and Jets in Astrophysics
G.S. Bisnovatyi-Kogan: Mechanism of Jet Formation
448 pages, hardbound, ISBN 0-7923-2521-4, 1993, Dfl 290.00/ 116.00 pounds
Kluwer Academic Publishers
P.O.Box 322
3300 AH Dordrecht
The Netherlands
Fax: (31) 78 183273
Herbig-Haro Object Catalog and Star Formation Newsletters available in Hypertext
Karen M. Strom[1]
[1] Five College Astronomy Dept., University of Massachusetts, Amherst, MA 01003
Webmaster
The Reipurth Herbig-Haro Object Catalog and the Star Formation Newsletters are now available in hypertext versions on the University of Massachusetts Astronomy World Wide Web Server. The catalog can be used in the standard manner by scanning the pages using the vertical scrollbar. The object number is linked to the note for that object. If the suspected source is also in the HBC, it is linked to the entry there. The references are linked to the entry in the list of references. If possible, those references are linked to the ADS Abstract server. Because so many references are very recent, I placed all issues of the Star Formation Newsletter on line in hypertext also, to provide the recent abstracts. There were approximately 25 references to papers between 1890 and 1960. Abstracts, first pages, or, in a few cases, the entire reference was obtained and placed on-line, linked to the reference list. We plan to update the references to these papers as they are published. A table of contents has been supplied for each issues, as well as a cumulative table of contents for ease in searches. These are linked directly to each abstract.
The URL for the home page of our server is:
http://www-astro.phast.umass.edu/
For the Reipurth Herbig-Haro Object Catalog:
http://www-astro.phast.umass.edu/latex/HHcat/HHcat.html
For the Star Formation Newsletters:
http://www-astro.phast.umass.edu/sfnews/index/
For the HBC:
http://www-astro.phast.umass.edu/latex/HBC/HBC.html