2. User Input File

The stellar input file contains all the metadata required for each star whose spectral energy distribution (SED) you wish to model. In the JSON parameterfile (see the Set-Up page) the file path is described as

['folders']['topdir']/['folders']['supportdir']/StellarInputFiles/user_input_stardata.xlsx

where, in the parameter file, and in the project repo example, it’s

twinkle-master/Inputs_and_Models/StellarInputFiles/user_input_stardata.xlsx.

The input file is an excel file, with a header where each column corresponds to a different meta-data parameter for each star. Each subsequent line contains information for a different star.

You can have multiple sheets in your excel file – maybe you want to have different versions of the same input data. You can specify which sheet you want to use through the ['files']['input_stars_sheet'] parameter in the JSON parameterfile.

Below is a simple stellar input file (broken up for easier viewing, but it would be a 3 row by 20 column file) that includes optical photometric data and some mid-infrared WISE data. You can download the contents of this input file and others here.

MainName

spt

SPT2HIP

NoOptical

model

temp

Star_ID1

A2V

A

FALSE

NextGen

8000

Star_ID2

B5V

F

TRUE

ATLAS9

8000

grav

met

plx

e_Plx

B-V

e_B-V

BJm

BJme

40

0

15.6

0.25

0.07

0.001

5.2

0.01

45

0

20

0.3

0.1

0.001

5.7

0.01

VJm

VJme

W1m

W1me

W2m

W2me

5.1

0.01

4.9

0.07

4.6

0.04

5.9

0.01

6.2

0.07

4.6

0.04

The file shows meta-data for two stars, Star_ID1, and Star_ID2 under the MainName column. All the columns up to e_B-V are not optional. This of course implies that the photometric columns are optional. You don’t technically need to include any photometric bands, besides Johnson B & V but then you wouldn’t get anything modeled. So you SHOULD include SOME photometric bands.

Important

For the moment, one must include the Johnson B and V photometry and uncertainties (BJm, BJme, VJm, VJme).

A full stellar input file can be found in the project repo here. You’ll see a number of different columns that you can use for your simulation. The file Input_StarFile_Description.xlsx (also included in the project repo) contains information for all acceptable meta-data columns in your input stellar file, as well as column Descriptions, Data Type, Units, parameter restrictions, examples of the data, and whether the column is optional for the simulation or not. The image and truncated/scrollable table shows what you’ll find in the Input_StarFile_Description.xlsx file.

Screenshot of the contents of the user input description file. Interactive one below.
Description of meta-data that can be found and used in the stellar input file.
Scroll vertically and horizontally to see the full file.

Optional Column?

COLUMN NAME

DESCRIPTION

Data Type

Units

Restricted Options

Example

Comment

No

MainName

Star Name [no spaces]

str

Star_ID1

Yes

OtherName

Alternative star identifier

str

Star_ID2

No

spt

Spectral Type

str

A2V

Yes

sptViz

Vizier listed Spectral Type

str

A2V

No

SPT2HIP

Spectral Letter

str

B,A,F,G,K,M

A

No

NoOptical

Remove Optical Photometry from Fit?

bool

True,False

False

No

model

Model type (NextGen or ATLAS9)

str

NextGen,ATLAS9

NextGen

No

temp *

Initial guess for stellar temperature

float

Kelvin

[2000,10000]

5000

No

grav *

gravity guess. log(g)

float

10 * log10(g[cm/s^2])

[35,40,45,50]

40

No

met

metallicity - should be set to 0 right now

int

0

0

Solar metallicity

Yes

Otype

Object Type

str

Star

No

plx

parallax

float

mas

>0

15.6

No

e_Plx

parallax unc.

float

mas

>0

0.25

No

B-V

Johnson B-V color

float

mag

0.072

No

e_B-V

Johnson B-V color unc.

float

mag

0.001

No

BJm

Johnson B mag

float

mag

5.242

No

BJme

Johnson B mag unc.

float

mag

0.009973956

No

VJm

Johnson V mag

float

mag

5.17

No

VJme

Johnson V mag unc.

float

mag

0.009923699

Yes

BT-VT

Tycho B-V color

float

mag

0.086

Yes

e_BT-VT

Tycho B-V color unc.

float

mag

0.016643317

Yes

Bt-Vt_corr

Corrected Tycho B-V color

float

mag

0.086

Yes

Vtmag

Tycho V mag

float

mag

5.175

Yes

eVtmag

Tycho V mag unc.

float

mag

0.009

Yes

Btmag

Tycho B mag

float

mag

5.261

Yes

eBtmag

Tycho B mag unc.

float

mag

0.014

Yes

J2Mm

2MASS J mag

float

mag

5.085

Yes

J2Mme

2MASS J mag unc.

float

mag

0.02

Yes

H2Mm

2MASS H mag

float

mag

5.057

Yes

H2Mme

2MASS H mag unc.

float

mag

0.018

Yes

Ks2Mm

2MASS Ks mag

float

mag

4.926

Yes

Ks2Mme

2MASS Ks mag unc.

float

mag

0.021

Yes

W1m

WISE W1 mag

float

mag

4.957

Yes

W1me

WISE W1 mag unc.

float

mag

0.077

Yes

W1mC ***

WISE W1 corrected mag ***

float

mag

4.929759941

Yes

W1meC ***

WISE W1 corrected mag unc. ***

float

mag

0.077210686

Yes

W2m

WISE W2 mag

float

mag

4.634

Yes

W2me

WISE W2 mag unc.

float

mag

0.04

Yes

W2mC ***

WISE W2 corrected mag ***

float

mag

4.938947781

Yes

W2meC ***

WISE W2 corrected mag unc. ***

float

mag

0.040660669

Yes

W3m

WISE W3 mag

float

mag

4.953

Yes

W3me

WISE W3 mag unc.

float

mag

0.014

Yes

w3mC ***

WISE W3 Corrected mag ***

float

mag

4.953

Yes

w3meC ***

WISE W3 Corrected mag unc. ***

float

mag

0.014

Yes

W4m

WISE W4 mag

float

mag

4.822

Yes

W4me

WISE W4 mag unc.

float

mag

0.026

Yes

ESNR

Excess SNR - calculated for WISE excesses from Patel et al., 2014

float

5

Yes

OtherFlux

Long wavelength bands used

str

HPACS160,HPACS100,Akari90

Applicable with plot_sed.py

Yes

MIPS70_flux

MIPS 70 flux

float

Jy

N/A

Add only when necessary

Yes

MIPS160_flux

MIPS 160 flux

float

Jy

N/A

Add only when necessary

Yes

HPACS70_flux

Herschel 70 flux

float

Jy

N/A

Add only when necessary

Yes

fluxHPACS160

Herschel 160 flux

float

Jy

0.2809

Add only when necessary

Yes

efluxHPACS160

Herschel 160 flux unc.

float

Jy

0.0503

Add only when necessary

Yes

fluxHPACS100

Herschel 100 flux

float

Jy

0.6244

Add only when necessary

Yes

efluxHPACS100

Herschel 100 flux unc.

float

Jy

0.011

Add only when necessary

Yes

fluxAkari90

Akari 90 flux

float

Jy

0.913

Add only when necessary

Yes

efluxAkari90

Akari 90 flux unc.

float

Jy

0.14

Add only when necessary

The photometric bands that can be used to calculate the SED and excess flux are listed in the file located ~/Inputs_and_Models/RSR/available_filters.txt. More information on the relative spectral response (RSR) files can be found on the Model Data Page.

To see what the output of the modeling would look like with different meta-data in the stellar input file, check out the Jupyter Notebook tutorial.

Important

The column strings should not have the asterisks. If the * columns are not included, then the ** columns in the “optional” column are required. If the *** columns are included, then “changekeys” in the JSON file must be set to “true” for these columns to be used.

Important

To include spectral data columns, the parameter names should be in the following format: [band]m, [band]me, [band]_flux, [band]_fluxe. If the data is photometric, use [band]m, and [band]me, and the other two for fluxes in Jy.