4. FAQs

  1. 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.
  2. 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”).
  3. 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.
  4. 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.
  5. 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”.
  6. 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.
  7. 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.