4. FAQs¶
- Q: What is the unit of photometric data in the input data file?
- A: The photometric data in the input data file must be flux and flux error in unit of uJy.
- Q: Is there any particular requirement for the order of data in the input file?
- A: The order of data in the input file must be consistent with the order of filters used in “–filters_selected observation/ULTRAVISTA/filters_selected.txt” with “iused=1”. Here, “iused=1” means there are data for the given filter in the input data file, but you can use it or not in the fitting by setting iselected=1 or 0. For example, in the example input file, we have used 30 filters, as shown by the first line “# ULTRAVISTA0 30 0”. The name of used filters is shown in the second line of the input file. So, the order of filters in observation/ULTRAVISTA/filters_selected.txt” (“Ks H J Y 8.0micron 5.8micron 4.5micron 3.6micron z+ i+ r+ Vj g+ Bj u* IA484 IA527 IA624 IA679 IA738 IA768 IA427 IA464 IA505 IA574 IA709 IA827 FUV NUV 24micron”) is the same as that in the input file(“Ks eKs H eH J eJ Y eY ch4 ech4 ch3 ech3 ch2 ech2 ch1 ech1 zp ezp ip eip rp erp V eV gp egp B eB u eu IA484 eIA484 IA527 eIA527 IA624 eIA624 IA679 eIA679 IA738 eIA738 IA767 eIA767 IB427 eIB427 IB464 eIB464 IB505 eIB505 IB574 eIB574 IB709 eIB709 IB827 eIB827 fuv efuv nuv enuv mips24 emips24”).
- Q: If some of the galaxies in the catalog don’t have data in a certain band, what should I use to indicate the absence of data to the code?
- A: You can indicate the absence of data by setting the flux and flux error to -99.
- Q: Where can I find the stellar mass of the best fit model of each galaxy?
- A: The estimation of all parameters is in a *.bayesed file. For any parameter of the model, the code gives many estimations (e.g., mass/Msol^{mean} mass/Msol^{sigma} mass/Msol^{MAL} mass/Msol^{MAP} mass/Msol^{median} mass/Msol^{lowerq} mass/Msol^{upperq}). “mass/Msol^{MAL}” is the stellar mass of the best fit model.
- Q: How to obtain photo-z with BayeSED?
- A: Set the range of allowed redshift by z_min and z_max for each galaxy in the input file. Here, different galaxy may have different z_min and/or z_max. If you have your estimation of redshift, you can set z_min=z_max=”your z_photo or z_spec”.
- Q: What is “E(B-V)” in the input file?
- A: It is about the dust extinction of the Milky Way. If it has been considered in your data, just set it to be 0.
- Q: There are some additional columns in the input file. Are they necessary?
- A: No. The input file allow some additional informations about the galaxy in columns behind the columns for the flux and flux err. These informations will be copied to the output *.bayesed file.