J/A+A/710/A38 Vertical structure of protoplanetary disks (Byrne+, 2026)
Vertical structure of protoplanetary disks in scattered light:
A large sample analysis.
Byrne J., Ginski C., van Capelleveen R.F., Fitzgerald N., Garufi A.,
Coyne C., Lawlor C., McLachlan D.
<Astron. Astrophys. 710, A38 (2026)>
=2026A&A...710A..38B 2026A&A...710A..38B (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Morphology ; Optical
Keywords: techniques: polarimetric - planets and satellites: formation -
protoplanetary disks - planet-disk interactions
Abstract:
High-resolution imaging in scattered light has revealed complex
morphologies in protoplanetary/circumstellar disks. Measuring their
vertical height is key to understanding disk structure, evolution, and
the properties of embedded dust.
This work aims to develop a robust methodology for fitting elliptical
shapes to scattered light images of protoplanetary disks in order to
extract vertical height profiles of the dust scattering surface
(tau=1) across a large and morphologically diverse disk sample. The
dataset comprises 92 unique near-infrared polarimetric images of
individual systems obtained with VLT/SPHERE. The goal is to identify
trends in vertical structure across morphologies and test for
correlations with stellar mass, age, and disk dust mass. Using the
height profiles, this work also investigates the implications of the
constrained height for the masses of potential embedded planets.
A structure extraction and ellipse fitting (SEEF) algorithm, is
implemented using edge detection and Gaussian fitting to locate the
structure within protoplanetary disks. Fitting ellipses to the
structure reveals spatial offsets from the centre of the ellipse and
the star, interpreted as vertical height assuming circular ring
geometry. Disk inclination, position angle (PA), and aspect ratio
(htau=1/r) are also derived.
The SEEF algorithm obtained successful vertical height measurements
for 92 unique disks, revealing variations in height profiles
consistent with flared disk geometries. Analysis of the full sample
shows that the vertical height profile cannot be confidently described
by a single power-law relation. Subdivision of the sample by disk
morphology revealed no strong correlations within most categories,
with the exception of extended disks (router≥150au), which
exhibited a strong correlation with a single power-law trend.
Investigation into underlying disk properties revealed no correlation
for its affect to the vertical height structure.
This work presents a consistent methodology for measuring the vertical
structure of circumstellar disks using ellipse fitting on scattered
light images. While trends in height structure remain weakly
correlated for the full sample and many disk morphologies, extended
disks (router≥150au) stand out as the only subgroup showing a
clear power-law flaring trend. The lack of a strong correlation across
other morphologies and with system properties like stellar or dust
mass suggests that either differing disk morphologies exhibit
different vertical height profiles or that another, unidentified
factor is influencing the disk flaring.
Description:
This catalogue contains geometrical parameters of circumstellar disks
derived from ellipse fitting of scattered-light ring structures, as
well as planet mass estimates inferred from disk gap properties.
TableA1 contains the measured geometrical parameters of disk rings,
including the disk height, inclination, separation, aspect ratio
(h/r), and position angle of the major axis for each disk region
(Inner, Middle, or Outer).
TableH1 contains estimated planet masses derived from measured gap
widths using the analytical model of Kanagawa et al.
(2016PASJ...68...43K 2016PASJ...68...43K). Planet masses are calculated assuming three
values of the disk viscosity parameter
alpha_visc=10-2, 10-3, and 10-4.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 101 128 Geometrical parameters of disk rings
tableh1.dat 80 28 Estimated planet masses derived from measured
gap widths using the analytical model of
Kanagawa et al. (2016PASJ...68...43K 2016PASJ...68...43K)
list.dat 205 91 List of fits datacubes
fits/* . 91 Individual fits datacubes
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 28 A28 --- Name Target name
30- 38 A9 --- Region Disk region (Inner, Middle, Outer)
40- 45 F6.2 au Height Disk height
47- 51 F5.2 au e_Height Uncertainty on Height
53- 57 F5.2 deg Incl Disk inclination
59- 62 F4.2 deg e_Incl Uncertainty on Incl
64- 69 F6.2 au Sep Ring separation
71- 74 F4.2 au e_Sep Uncertainty on Sep
76- 79 F4.2 --- h/r Aspect ratio (h/r)
81- 84 F4.2 --- e_h/r Uncertainty on h/r
86- 91 F6.2 deg PA Position angle of disk major axis (1)
93- 97 F5.2 deg e_PA Uncertainty on PA
99 A1 --- PAref [Y/N] Position-angle reference flag (2)
101 A1 --- Constr [Y/N] Parameter constraint flag (3)
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Note (1): The standard position angle (PA) convention is measured from North
through East to the first instance of the major axis such that the
forward-scattering side lies between this axis and its opposite.
Note (2): If PAref='Y', the PA is instead measured from the +y axis to the
first instance of the major axis in the counter-clockwise direction.
This definition is used when the forward-scattering side could not
be determined.
Note (3): Parameter constraint flag as follows:
Y = indicates that the geometrical parameters were considered constrained
by the fitting procedure
N = indicates they were not constrained
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Byte-by-byte Description of file: tableh1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 24 A24 --- System Target system name
25- 29 F5.1 au GapWidth Measured gap width
31- 34 F4.1 au e_GapWidth Uncertainty on GapWidth
36- 40 F5.1 au Rp Planet semi-major axis
42- 44 F3.1 au e_Rp Uncertainty on Rp
46- 50 F5.3 --- h/r Disk aspect ratio (h/r) at Rp
52- 55 F4.2 MJup Mpa1e2 Planet mass for alphavisc=10-2 (1)
57- 60 F4.2 MJup e_Mpa1e2 Uncertainty on Mpa1e2
62- 65 F4.2 MJup Mpa1e3 Planet mass for alphavisc=10-3 (1)
67- 70 F4.2 MJup e_Mpa1e3 Uncertainty on Mpa1e3
72- 75 F4.2 MJup Mpa1e4 Planet mass for alphavisc=10-4 (1)
77- 80 F4.2 MJup e_Mpa1e4 Uncertainty on Mpa1e4
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Note (1): Planet masses are estimated using the analytical relation derived
by Kanagawa et al. (2016PASJ...68...43K 2016PASJ...68...43K), assuming three values of the disk
viscosity parameter alphavisc=10-2, 10-3, and 10-4.
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 28 A28 --- Name Star name
31- 39 F9.5 deg RAdeg Right Ascension of center (J2000)
40- 48 F9.5 deg DEdeg Declination of center (J2000)
50- 53 I4 --- Nx Number of pixels along X-axis
55- 58 I4 --- Ny Number of pixels along Y-axis
60 I1 --- Nz Number of pixels along Z-axis
62- 66 I5 Kibyte size Size of FITS file
68-150 A83 --- FileName Name of FITS file, in subdirectory fits
152-205 A54 --- Title Title of the FITS file
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Acknowledgements:
Jake Byrne, Jakebyrne1710(at)gmail.com
License: CC-BY-4.0
(End) Patricia Vannier [CDS] 22-Apr-2026