J/A+A/441/195 Circumstellar disks in Trapezium cluster (Vicente+, 2005)
Size distribution of circumstellar disks in the Trapezium cluster.
Vicente S.M., Alves J.
<Astron. Astrophys., 441, 195 (2005)>
=2005A&A...441..195V 2005A&A...441..195V
ADC_Keywords: Stars, pre-main sequence ; Planets ; Stars, distances
Keywords: stars: planetary systems: protoplanetary disks -
stars: planetary systems: formation - stars: pre-main sequence -
stars: low-mass, brown dwarfs - stars: formation
Abstract:
In this paper we present results on the size distribution of
circumstellar disks in the Trapezium cluster as measured from
HST/WFPC2 data. Direct diameter measurements of a sample of 135 bright
proplyds and 14 silhouettes disks suggest that there is a single
population of disks well characterized by a power-law distribution
with an exponent of -1.9±0.3 between disk diameters 100-400AU.
For the stellar mass sampled (from late G to late M stars) we find no
obvious correlation between disk diameter and stellar mass. We also
find that there is no obvious correlation between disk diameter and
the projected distance to the ionizing Trapezium OB stars. We estimate
that about 40% of the disks in the Trapezium have radius larger than
50AU. We suggest that the origin of the Solar system's (Kuiper belt)
outer edge is likely to be due to the star formation environment and
disk destruction processes (photo-evaporation, collisions) present in
the stellar cluster on which the Sun was probably formed. Finally, we
identified a previously unknown proplyd and named it 266-557,
following convention.
Description:
To perform the diameter measurements we selected from the available
Hubble Space Telescope (HST) images of the Orion Nebula (Bally et al.,
2000AJ....119.2919B 2000AJ....119.2919B, the HST mosaicked "master" images of the Orion
Nebula are accessible at
http://casa.colorado.edu/~bally/HST/HST/master/ ) the one that
provided the best contrast between the disk and the background nebula
light. The available images are mosaic images from data acquired
through filters F673N, F658N, F656N, F631N, F547N and F502N, under the
general observer (GO) programs, GO 5085 (O'Dell & Wong, 1996, Cat.
J/AJ/111/846) and GO 5469 (Bally et al., 1998AJ....116..293B 1998AJ....116..293B;
O'Dell, 1998AJ....115..263O 1998AJ....115..263O). After quantitative comparisons we
selected the Halpha image since it provided the best contrast and had
the best signal-to-noise.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 86 162 Catalog of 162 Orion proplyds observational
properties.
--------------------------------------------------------------------------------
See also:
J/AJ/111/846 : Orion HST survey (O'Dell+ 1996)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- [OW94] Name, as in O'Dell & Wong (1996, J/AJ/111/846)
12 I1 h RAh ?=- Right ascension (J2000)
14- 15 I2 min RAm ?=- Right ascension (J2000)
17- 21 F5.2 s RAs ?=- Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24 I1 deg DEd ?=- Declination (J2000)
26- 27 I2 arcmin DEm ?=- Declination (J2000)
29- 32 F4.1 arcsec DEs ?=- Declination (J2000)
34- 37 F4.1 pix Ddiskp ?=- Disk diameter, in pixel (1)
39- 42 I4 AU Ddisk ?=- Disk diameter, in AU (1)
44- 47 F4.1 pix DIFp ?=- Ionisation front (IF) diameter, in pixel (1)
49- 52 I4 AU DIF ?=- Ionisation front (IF) diameter, in AU (1)
54- 58 F5.1 arcsec Dproj ?=- Projected distance to θ1 OriC
60- 86 A27 --- Comm Comments (2)
--------------------------------------------------------------------------------
Note (1): The disk and IF diameters were determined directly from the data
and do not account for finite size of the HST PSF.
Note (2): Includes the reference for the 10 bright proplyds with visible
embedded disks, the 16 pure silhouettes and the 14 objects listed
in previous papers but not found in the Hα image. For 4
of these objects, the IF and disk diameters were measured from their
images published in the papers O'Dell & Wen (1994ApJ...436..194O 1994ApJ...436..194O,
OW94) and Bally et al. (2000AJ....119.2919B 2000AJ....119.2919B, BOM).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Jul-2006