IGMSurvey Class¶
IGMSurvey¶
This Class is designed to organize and analyze a survey of absorption systems (defined as AbsSystem objects).
By definition, an IGMSurvey is a unique collection of AbsSystem objects. It is specified by the number of systems and the references.
Instantiation¶
The AbsSystem Class may be instantiated in a few ways. The default sets the properties listed above:
gensurvey = GenericIGMSurvey()
More commonly, one will instantiate with one or more IGMSystem objects:
coord = SkyCoord(ra=123.1143*u.deg, dec=-12.4321*u.deg)
gensys = IGMSystem('MgII', coord, 1.244, [-300,300.]*u.km/u.s, NHI=16.)
gensys.name = 'Sys1'
#
coord2 = SkyCoord(ra=223.1143*u.deg, dec=42.4321*u.deg)
gensys2 = IGMSystem('MgII', coord2, 1.744, [-300,300.]*u.km/u.s, NHI=17.)
gensys2.name = 'Sys2'
#
gensurvey.add_abs_sys(gensys1)
gensurvey.add_abs_sys(gensys2)
Attributes/Properties¶
| Variable | Type | Description |
|---|---|---|
| nsys | int | Number of systems in the survey |
| ref | str | References for the survey |
Sub Classes¶
LLS¶
Subclass for an LLS survey. There are many published surveys that can be read in. Several require access to the Internet which will then generate a file on your drive for future use. There is also a method to handle the .dat and .lst files used by JXP. See Examples for LLSSurvey (v1.5) for more.
Here is a Table describing the various samples that may be accessed.
| Survey | Call | Reference(s) | Description |
|---|---|---|---|
| SDSS | LLSSurvey.load_SDSS_DR7() | Prochaska+10 | tau>2 survey |
| z2_HST | LLSSurvey.load_HST_ACS() LLSSurvey.load_HST_WFC3() | Omeara+11 Omeara+11 | tau>2 with HST/ACS tau>1 with HST/WFC3 |
| z3_MagE | LLSSurvey.load_mage_z3() | Fumagalli+13 | tau>2 with Magellan/MagE |
| HD-LLS | LLSSurvey.load_HDLLS() | Prochaska+15 Fumagalli+16 | Ionic column densities and metallicity PDF |
| Literature | lls_literature.load_lls_lit() | See Fumagalli+16 | Ionic column densities |
Below are additional options for a few of these.
HD-LLS DR1¶
The standard call loads the ionic column densities and metallicity PDFs. One call access the spectra with:
hdlls = LLSSurvey.load_HDLLS(grab_spectra=True)
This will grab 154Mb of data from the internet, and place them within pyigm/data/LLS/HD-LLS.
DLAs¶
Subclass for DLASurvey. Presently handles the .dat and .lst files used by JXP. See DLASurvey_examples for more.
Here is a Table describing the various DLA surveys that may be loaded and manipulated.
| Survey | Call | Reference(s) | Description |
|---|---|---|---|
| HST16 | DLASurvey.load_HST16() | Neeleman+16 | Blind survey of HST UV spectra |
| H100 | DLASurvey.load_H100() | Neeleman+13 | 100 unbiased HIRES spectra |
| SDSS_DR5 | DLASurvey.load_SDSS_DR5() | PW09 | DR5 |
| P03 | DLASurvey.load_P03() | P03 | Compilation by Peroux et al. |
| G09 | DLASurvey.load_G09() | G09 | Compilation by Guimaraes et al. |
| GGG | DLASurvey.load_GGG() | GGG | Giant Gemini GMOS survey |
| XQ100 | DLASurvey.load_XQ100() | XQ100 | Survey of XQ-100 spectra |
See DLASurvey_examples for usage example.
Plots¶
Methods¶
g(z)¶
Provide the sightlines Table is filled and has keys Z_START and Z_END, this method will generate a selection function \(g(z)\) curve:
# LLS
z3mage = LLSSurvey.load_mage_z3()
zeval, gz = z3mage.calculate_gz()
# DLA
sdss = DLASurvey.load_SDSS_DR5()
zeval, gz = sdss.calculate_gz()
f(N,X)¶
Calculate the NHI frequency distribituion in bins of NHI and z. e.g.,
fN, fN_lo, fN_hi = sdss_stat.calculate_fn([20.3, 20.5, 21., 21.5, 22.], [2, 2.5], log=True)
Setting log=True returns log10 values for f(N) and its error.
l(X)¶
Calculate the incidence per unit dX in binned redshift intervals. Default is over all NHI values. Here is an example:
lX, lX_lo, lX_hi = sdss_stat.calculate_lox([2., 2.5, 3])
This calculates lX and its error in the intervals z=[2,2.5] and z=[2.5,3.].
rhoHI¶
Similar to the last two methods but now for the HI mass density. Here is an example:
zbins = [2., 2.5, 3.]
NHImnx = (20.3, 23.)
rho, rho_lo, rho_hi = sdss_stat.calculate_rhoHI(zbins, NHImnx)
rho will have units of Solar mass per Mpc^3.