J/A+A/665/A68 Modeling snowline locations in protostars (Murillo+, 2022)
Modeling snowline locations in protostars:
The impact of structure of protostellar cloud cores.
Murillo N.M., Hsieh T.-H., Walsh C.
<Astron. Astrophys. 665, A68 (2022)>
=2022A&A...665A..68M 2022A&A...665A..68M (SIMBAD/NED BibCode)
ADC_Keywords: Models
Keywords: astrochemistry - stars: formation - stars: low-mass - ISM: molecules -
methods: numerical
Abstract:
Snowlines during star and disk formation are responsible for a range
of effects during the evolution of protostars, such as setting the
chemical composition of the envelope and disk. This in turn influences
the formation of planets by changing the elemental compositions of
solids and affecting the collisional properties and outcomes of dust
grains. Snowlines can also reveal accretion bursts, providing insight
into the formation process of stars. A numerical chemical network
coupled with a grid of cylindrical-symmetric physical models was used
to identify what physical parameters alter the CO and H2O snowline
locations. The investigated parameters are the initial molecular
abundances, binding energies of CO and H2O, heating source, cloud
core density, outflow cavity opening angle, and disk geometry.
Simulated molecular line emission maps were used to quantify the
change in the snowline location with each parameter. The models
presented in this work show that the CO and H2O snowline locations
do not occur at a single, well-defined temperature as is commonly
assumed. Instead, the snowline position depends on luminosity, cloud
core density, and whether a disk is present or not. Inclination and
spatial resolution affect the observability and successful measurement
of snowline locations. We note that N2H+ and HCO+ emission serve as
good observational tracers of CO and H2O snowline locations.
However, constraints on whether or not a disk is present, the
observation of additional molecular tracers, and estimating envelope
density will help in accurately determining the cause of the observed
snowline position. Plots of the N2H+ and HCO+ peak emission radius
versus luminosity are provided to compare the models with observations
of deeply embedded protostars aiming to measure the CO and H2O
snowline locations.
Description:
Physico-chemical models of snowline locations in protostars, focusing
on studying the effect of the physical structure of low-mass embedded
protostellar systems on snowline location. Molecular distributions are
calculated from a numerical chemical network coupled with a grid of
cylindrical-symmetric (2D) physical models. The calculated molecular
distributions are used to produce simulated emission data cubes for
N2H+ 1-0 and HCO+ 3-2. Integrated intensity maps of N2H+ and HCO+
are produced from the data cubes. The physical models are used to
derive spectral energy distributions (SEDs). Based on the integrated
intensity maps and SEDs, tables of luminosity versus simulated
emission peak position are derived for the luminosity range 0.01 to
200L☉. The integrated intensity maps, SEDs, and luminosity
versus peak positions are provided at seven inclinations: 0 deg
(face-on), 15, 25, 45, 65, 75, 90 (edge-on).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
md_prm.dat 62 1078 List of calculated molecular distribution model
names and corresponding physical parameters
models/* . 1078 Calculated molecular distribution model data
sed_prm.dat 66 7546 List of spectral energy distributions (SED)
model names and corresponding physical
parameters
sed/* . 7546 Modeled spectral energy distribution data for
inclination i
lcpn_prm.dat 55 98 List of central luminosity versus N2H+ peak
position table names and corresponding physical
parameters of the model set
lcpn/* . 98 Table of central luminosity versus N2H+ peak
position data for the luminosity range
0.01 to 200L☉
lbpn_prm.dat 56 98 List of bolometric luminosity versus N2H+ peak
position table names and corresponding physical
parameters of the model set
lbpn/* . 98 Table of bolometric luminosity versus N2H+ peak
position data for the luminosity range
0.01 to 200L☉
lcph_prm.dat 55 98 List of central luminosity versus HCO+ peak
position table names and corresponding physical
parameters of the model set
lcph/* . 98 Table of central luminosity versus HCO+ peak
position data for the luminosity range
0.01 to 200L☉
lbph_prm.dat 56 98 List of bolometric luminosity versus HCO+ peak
position table names and corresponding physical
parameters of the model set
lbph/* . 98 Table of bolometric luminosity versus HCO+ peak
position data for the luminosity range
0.01 to 200L☉
fits_prm.dat 108 7700 List of simulated N2H+ and HCO+ emission
integrated intensity maps with corresponding
model parameters
fits/* . 15400 Individual fits files
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Byte-by-byte Description of file: md_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- MDFileName Model FileName, in subdirectory models
(csv file with one hearder line)
13- 19 E7.2 Msun Mdisk Disk mass
21- 27 F7.3 Lsun Lcen Central luminosity of the protostar
29- 31 I3 AU Rdisk Disk radius
33- 36 F4.2 --- Hdisk Disk scale height, dimensionless ratio
38- 43 E6.2 cm-3 rhoenv Envelope density
45- 47 I3 deg Thetaout Outflow cavity opening angle
49- 52 I4 K EbCO Binding energy for CO
54- 57 I4 K EbH2O Binding energy for H2O
59- 62 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Description of file: models/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 E12.8 AU r Position in the r-direction
13 A1 --- --- [,]
14- 25 E12.8 AU zz Position in the z-direction
26 A1 --- --- [,]
27- 38 E12.7 cm-3 n Density at (r,zz)
39 A1 --- --- [,]
40- 51 E12.7 K T Temperature at (r,zz)
52 A1 --- --- [,]
53- 64 E12.8 --- XGCO Abundance of XGCO w.r.t. H2
65 A1 --- --- [,]
66- 77 E12.8 --- XGN2 Abundance of XGN2 w.r.t. H2
78 A1 --- --- [,]
79- 90 E12.8 --- XGH2O Abundance of XGH2O w.r.t. H2
91 A1 --- --- [,]
92-103 E12.8 --- XH3O+ Abundance of XH3O+ w.r.t. H2
104 A1 --- --- [,]
105-116 E12.8 --- XH2+ Abundance of XH2+ w.r.t. H2
117 A1 --- --- [,]
118-129 E12.8 --- XH2O Abundance of XH2O w.r.t. H2
130 A1 --- --- [,]
131-142 E12.8 --- XHD Abundance of XHD w.r.t. H2
143 A1 --- --- [,]
144-155 E12.8 --- XDCO+ Abundance of XDCO+ w.r.t. H2
156 A1 --- --- [,]
157-168 E12.8 --- XN2D+ Abundance of XN2D+ w.r.t. H2
169 A1 --- --- [,]
170-181 E12.8 --- XN2H+ Abundance of XN2H+ w.r.t. H2
182 A1 --- --- [,]
183-194 E12.8 --- XHCO+ Abundance of XHCO+ w.r.t. H2
195 A1 --- --- [,]
196-207 E12.8 --- XGRAIN- Abundance of XGRAIN- w.r.t. H2
208 A1 --- --- [,]
209-220 E12.8 --- XGRAIN0 Abundance of XGRAIN0 w.r.t. H2
221 A1 --- --- [,]
222-233 E12.8 --- XH3+ Abundance of XH3+ w.r.t. H2
234 A1 --- --- [,]
235-246 E12.8 --- XH2D+ Abundance of XH2D+ w.r.t. H2
247 A1 --- --- [,]
248-259 E12.8 --- XN2 Abundance of XN2 w.r.t. H2
260 A1 --- --- [,]
261-272 E12.8 --- XCO Abundance of XCO w.r.t. H2
273 A1 --- --- [,]
274-285 E12.8 --- XD Abundance of XD w.r.t. H2
286 A1 --- --- [,]
287-298 E12.8 --- XH2 Abundance of XH2 w.r.t. H2
299 A1 --- --- [,]
300-311 E12.8 --- XH Abundance of XH w.r.t. H2
312 A1 --- --- [,]
313-324 E12.8 --- Xe- Abundance of Xe- w.r.t. H2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sed_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- SEDFileName SED model FileName, in subdirectory sed
(csv file with one hearder line)
14- 15 I2 deg incl Inclination angle, 0 (face-on), 90 (edge-on)
17- 23 E7.2 Msun Mdisk Disk mass
25- 31 F7.3 Lsun Lcen Central luminosity of the protostar
33- 35 I3 AU Rdisk Disk radius
37- 40 F4.2 --- Hdisk Disk scale height, dimensionless ratio
42- 47 E6.2 cm-3 rhoenv Envelope density
49- 51 I3 deg Thetaout Outflow cavity opening angle
53- 56 I4 K EbCO Binding energy for CO
58- 61 I4 K EbH2O Binding energy for H2O
63- 66 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Description of file: sed/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 E12.8 um lambda Wavelength
13 A1 --- --- [,]
14- 25 E12.9 W/m2/Hz Flux Flux at corresponding wavelength and
inclination i (indicated in filename)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lcpn_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- LcPNFileName Central luminosity vs N2H+ peak position
table name, in subdirectory lcpn
(csv file with one hearder line)
14- 20 E7.2 Msun Mdisk Disk mass
22- 24 I3 AU Rdisk Disk radius
26- 29 F4.2 --- Hdisk Disk scale height, dimensionless ratio
31- 36 E6.2 cm-3 rhoenv Envelope density
38- 40 I3 deg Thetaout Outflow cavity opening angle
42- 45 I4 K EbCO Binding energy for CO
47- 50 I4 K EbH2O Binding energy for H2O
52- 55 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lbpn_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- LbPNFileName Bolometric luminosity vs N2H+ peak
position table name, in subdirectory lbpn
(csv file with one hearder line)
14- 20 E7.2 Msun Mdisk Disk mass
22- 24 I3 AU Rdisk Disk radius
26- 29 F4.2 --- Hdisk Disk scale height, dimensionless ratio
31- 37 E7.2 cm-3 rhoenv Envelope density
39- 41 I3 deg Thetaout Outflow cavity opening angle
43- 46 I4 K EbCO Binding energy for CO
48- 51 I4 K EbH2O Binding energy for H2O
53- 56 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lcph_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- LcPHFileName Central luminosity vs HCO+ peak position
table name, in subdirectory lcph
(csv file with one hearder line)
14- 20 E7.2 Msun Mdisk Disk mass
22- 24 I3 AU Rdisk Disk radius
26- 29 F4.2 --- Hdisk Disk scale height, dimensionless ratio
31- 36 E6.21 cm-3 rhoenv Envelope density
38- 40 I3 deg Thetaout Outflow cavity opening angle
42- 45 I4 K EbCO Binding energy for CO
47- 50 I4 K EbH2O Binding energy for H2O
52- 55 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lbph_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- LbPHFileName Bolometric lum vs HCO+ peak position
table name, in subdirectory lbph
(csv file with one hearder line)
14- 20 E7.2 Msun Mdisk Disk mass
22- 24 I3 AU Rdisk Disk radius
26- 29 F4.2 --- Hdisk Disk scale height, dimensionless ratio
31- 37 E7.2 cm-3 rhoenv Envelope density
39- 41 I3 deg Thetaout Outflow cavity opening angle
43- 46 I4 K EbCO Binding energy for CO
48- 51 I4 K EbH2O Binding energy for H2O
53- 56 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Description of file: lcpn/* lcph/* lbpn/* lbph/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 E12.8 Lsun Lcen Central luminosity
13 A1 --- --- [,]
14- 25 E12.8 AU Peakinc0 N2H+ peak position at inclination 0
26 A1 --- --- [,]
27- 38 E12.8 AU Peakinc15 N2H+ peak position at inclination 15
39 A1 --- --- [,]
40- 51 E12.8 AU Peakinc25 N2H+ peak position at inclination 25
52 A1 --- --- [,]
53- 64 E12.8 AU Peakinc45 N2H+ peak position at inclination 45
65 A1 --- --- [,]
66- 77 E12.8 AU Peakinc65 N2H+ peak position at inclination 65
78 A1 --- --- [,]
79- 90 E12.8 AU Peakinc75 N2H+ peak position at inclination 75
91 A1 --- --- [,]
92-103 E12.8 AU Peakinc90 N2H+ peak position at inclination 090
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fits_prm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- N2HFileName N2H+ datacube fits filename,
in subdirectory fits
14- 17 F4.2 arcsec N2Hbeamsize Beam size of the N2H+ datacube
19- 20 I2 arcsec N2Hmapsize Map size of the N2H+ datacube
22- 24 F3.1 arcsec N2Hpixsize Pixel size of the N2H+ datacube
26- 37 A12 --- HCOFileName HCO+ datacube fits filename,
in subdirectory fits
39- 42 F4.2 arcsec HCObeamsize Beam size of the N2H+ datacube
44 I1 arcsec HCOmapsize Map size of the N2H+ datacube
46- 49 F4.2 arcsec HCOpixsize Pixel size of the N2H+ datacube
51- 53 I3 pc Dist Adopted distance for the simulated datacubes
55- 56 I2 deg incl Inclination angle, 0 (face-on), 90 (edge-on)
58- 64 E7.2 Msun Mdisk Disk mass
66- 72 F7.3 Lsun Lcen Central protostar luminosity
74- 76 I3 AU Rdisk Disk radius
78- 81 F4.2 --- Hdisk Disk scale height, dimensionless ratio
83- 89 E7.2 cm-3 rhoenv Envelope density
91- 93 I3 deg Thetaout Outflow cavity opening angle
95- 98 I4 K EbCO Binding energy for CO
100-103 I4 K EbH2O Binding energy for H2O
105-108 I4 K Teff Central protostar effective temperature
--------------------------------------------------------------------------------
Acknowledgements:
Nadia Murillo Mejias, nadia.murillomejias(at)riken.jp
(End) Patricia Vannier [CDS] 20-Jun-2022