IGMSystem¶
Overview¶
The IGMSystem class is designed to organize and analyze an absorption system. This is generally constructed of one or more (AbsComponent). The base class is abstract, i.e. one must instantiate one of its flavors (e.g. HILyman, MgII, LLS, DLA).
By definition, an IGMSystem is a unique collection of absorption components. It is specified by:
| Property | Variable | Type | Description |
|---|---|---|---|
| RA, DEC | radec | tuple or coord | RA,DEC in deg or astropy.coordinate |
| Redshift | z | float | absorption redshift |
| Velocity limits | vlim | Quantity array | -/+ velocity limits of the system |
Instantiation¶
The IGMSystem Class may be instantiated in a few ways. The default sets the properties listed above:
gensys = GenericIGMSystem((15.23*u.deg,-23.22*u.deg), 1.244, [-500,500]*u.km/u.s, NHI=16.)
More commonly, one will instantiate with one or more AbsComponent objects:
# HI Lya, Lyb
radec = SkyCoord(ra=123.1143*u.deg, dec=-12.4321*u.deg)
lya = AbsLine(1215.670*u.AA,z=2.9239)
lya.analy['vlim'] = [-300.,300.]*u.km/u.s
lyb = AbsLine(1025.7222*u.AA)
lyb.analy['vlim'] = [-300.,300.]*u.km/u.s
lyb.setz(lya.attrib['z'])
abscomp = AbsComponent.from_abslines([lya,lyb])
abscomp.coord = radec
# Finish
HIsys = HISystem.from_components([abscomp])
Attributes¶
Sub Classes¶
Generic¶
A catch-all subclass for IGMSystem.
HI¶
A subclass for HI systems. All of the components are required to have Zion=(1,1).
LLS¶
An IGMSystem class for LLS. One is required to set the NHI keyword upon instantiation. See the Examples for the LLSSystem Class (v1.1.1) notebook for more.
DLA¶
An IGMSystem class for DLA. One is required to set the NHI keyword upon instantiation and it must equal or exceed 20.3. See the Examples for the DLASystem Class (v1.0) notebook for more.