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Page history last edited by Mark Lacy 10 years ago

ALMA simulation library

 

This Wiki contains a list of ALMA simulation projects which we hope to include into the ALMA Archive, for testing purposes and as examples to users.

Each of the projects is based around one or more scientific simulation datasets, produced by theorists, which serve as input science models to the ALMA simulator simdata(), which produces mock ALMA datasets that can be put into the ALMA archive along with the associated project datafiles generated by the Observe Tool.

 

The following is needed for each of the projects:

- science simulations

- a description of the dataset, and the choice of observing mode(s) and parameters

- a project datafile produced by the Observe Tools, tagged as a simulation project

 

Links to files at your home institution would be preferred, as diskspace is limited on this (free) wiki !

 

Some of the projects have links to proposed projects in the DRSP , but this is not required.

 

Please use free formatting for your project when editing this wiki: this whole page will be reformatted at some point, once we know what information should be there.

 


 

Molecular line emission model for a proto-planetary disk 

 

Observing mode: C17O(3-2) line emission at 337 GHz 

Author: Itziar de Gregorio-Monsalvo  (ALMA Fellow in Santiago)

 

corresponding DRSP project Nb 2.4.13 "Protoplanetary disks in Orion"  

 

description from the authors:

These are a set of molecular line emission models calculated for various mass accretion rates, radius, viscosity and maximum dust grain distributions.
We tried to reproduce a real interferometric observation of a protoplanetary disk with different physical parameters, we integrated the radiative transfer equation and convolved each model with a beam of 0."4.
The line selected was C17O(3-2) transition at 337 GHz (high excitation transition of a CO isotope with very low abundance, less susceptible to be affected by absorption and emission from the surrounding cloud material).
Some assumptions:
- we assume disk in steady state, with constant mass accretion rate and viscosity parameter alpha
- we assume gas and dust thermally coupled and vertical hydrostatic equilibrium.
 
Input parameters:
We considered typical parameters of a TTauri star (Mstar=0.5 Msun, Rstar=2Rsun, Tstar=4000 K) for all the models. We assume the disks are at 140 pc of distance (the distance to the Taurus molecular cloud), and with a disk inclination angle of 60degrees.
We have considered the next set of input physical parameters:
Rd (maximum disk radius) = 50, 100, 150 AU
a_max (maximum radius of dust grains)= 1,10,100,1000,10000,100000 microns
M_p (mass accretion rate)= 10e-09, 3x10e-08, 10e-07 M_sun/year
alpha (viscosity parameter)= 0.001, 0.005, 0.01, 0.02, 0.05
And we have built models for all the combinations (physically possible) of these physical parameters.

 

References: 

de Gregorio-Monsalvo, D'Alessio & Gomez (2007), Rev. Mex. de A y A, 43, 271

Gomez & D'Alessio (2000), ApJ, 535, 943 

 

Example simdata output:


 

CO(4-3) imaging of Lyman-break galaxies at z=3

 

Observing mode: CO(4-3) maps

Author: Thomas Greve (MPIA Heidelberg)

 

corresponding DRSP Nb 1.1.5 "Molecular line studies of submm galaxies"

or DRSP Nb 1.1.9 "Dust in normal Lyman Break galaxies"

 

description from the authors:

CO(4-3) maps (velocity-cubes)
The intensity units are simply Jy (I've multiplied with the solid angle of each pixel, so the units are Jy).
The velocity units are km/s
The pixel scale is 0.1kpc/px while the velocity resolution is 5km/s

 

Reference:

Greve & Sommer-Larsen (2008), A&A, 480, 335


 

CO imaging of comet Hale-Bopp

 

Observing mode: CO J2-1 map

Author: Jeremie Boissier (IRAM)

 

related to DRSP Nb 4.3.1 "A complete picture of Earth-grazing comet 103P/Hartley 2"

or DRSP Nb 4.3.5 "Is Hale-Bopp still alive ?"

 

description from the authors:

a model of the CO emission of comet Hale-Bopp computed on the basis of hydrodynamical simulations. The model assumes the presence of a CO jet creating a spiral structure.

 

256x256 pixels (0.5x0.5'' each)

 
RA: 22:31:17.798, DEC: 40:49:18.55
Units: Jy
reference frequency 230538.0 in channel 20 (CO J2-1)
40 channels of 0.1 km/s
Comet geocentric distance ~1.5 AU
Comet heliocentric distance ~1 AU
Production rate of water : 1.5e31 molecules/s
Production rate of water : 1.3e30 molecules/s
Sensitivity:
The sensitivity is not a limitation by itself in the case of a comet as bright as Hale-Bopp. The spectrum peak in the brightest pixel of the map is close to 1Jy. The important point is to make an image in a short integration time (<1h) in order to have successive snapshots of the coma and study the chinematics of the gas.

Ultradeep continuum survey

 
Observing mode: continuum band 7
Author: Eelco van Kampen (ESO)
 
 
description from the authors:
small area, deep pencil-beam surveys taken from cosmological simulations and phenomenological galaxy formation models. Many fields, including some containing overdensities (proto-clusters).

 

Imaging of molecular gas close to an AGN (see DRSP1.5.1)

Map the CO 2-1 (230GHz, band 6) and CO 3-2 (345GHz, band 7) lines at 0.1" resolution in a nearby Seyfert nucleus (NGC1068).

Tests high dynamic range imaging and high resolution mapping.

(MDL 2nd Feb)

 


 

 

 

 

PROJECTS WE WOULD LIKE TO INCLUDE:

 

- extra-galactic spectral line survey 

  (eg. DSRP 1.1.4: Unbiased survey of submm galaxies: line survey 210-275 GHz )

 

- galactic line survey

   Nearby cold cores (<10 km/s)

 

- proto-stars (sampling the IMF)

   Relatively high dynamic range and fidelity

 

- star forming regions

   Region with lots of structure: NGC1333

   (3D image fidelity)

 

- proto-stellar variability: timescale ~months

 

- gamma-ray bursts and/or supernovae

   (Lightcurve: time resolution, Targets-of-Opportunity)

 

 

 

- AGN variability

 

- SZ: total power and ACA

 

- extra-solar planets

 

 

 
 

 

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