The table below provides a compilation of emission-line parameters gathered through the development of the DAP. Many of them have not actually been fit by the DAP in any survey-level runs of the software and are simply collected here for reference.
Rest wavelengths are Ritz wavelengths in vacuum, collected from the NIST Atomic Spectra Database.
The "M1" and "E2" values are the Einstein Aki coefficients for the magnetic dipole and electric quadrupole transitions, respectively. These are collected to fix the expected flux ratio between specific line doublets. The expected flux ratio is:
where, e.g., λ1 is the rest wavelength of the first line in the doublet.
Additionally, we have defined some nominal passbands used for calculations of the line equivalent width (EW), including the main passband centered on the line and blue and red sidebands that are used to construct a linear continuum beneath the emission line.
Name | Rest λ (Å) | M1 | E2 | EW Passband (Å) | Blue Passband (Å) | Red Passband (Å) |
---|---|---|---|---|---|---|
HeII1 |
|
|||||
NeIII |
|
|||||
NeV |
|
1.38e-1 |
|
|||
NeV |
|
3.82e-1 |
|
|||
NI2 |
|
|||||
H25 |
|
|||||
H24 |
|
|||||
H23 |
|
|||||
H22 |
|
|||||
H21 |
|
|||||
H20 |
|
|||||
H19 |
|
|||||
H18 |
|
|||||
H17 |
|
|||||
H16 |
|
|||||
H15 |
|
|||||
H14 |
|
|
|
|||
OII |
|
1.59e-4 | 1.86e-5 |
|
|
|
OII |
|
1.98e-6 | 2.86e-5 |
|
|
|
H13 |
|
|
|
|||
H126 |
|
|
|
|
||
H117 |
|
|
|
|
||
|
|
|
|
|
||
|
|
|
|
|
||
NeIII |
|
1.74e-1 |
|
|
|
|
HeI10 |
|
|
|
|||
|
|
|
|
|
||
NeIII |
|
5.40e-2 |
|
|
||
|
|
|
|
|
||
HeI15 |
|
|
|
|
||
SII |
|
1.92e-1 | 9.53e-8 |
|
|
|
SII |
|
7.72e-2 | 1.16e-6 |
|
|
|
|
|
|
|
|
||
|
|
|
|
|
||
OIII |
|
1.71e+0 |
|
|
|
|
HeI18 |
|
|
|
|
||
HeII19 |
|
|
|
|
||
ArIV20 |
|
9.6e-3 | ||||
HeI21 |
|
|
|
|
||
ArIV |
|
|
|
|||
|
|
|
|
|
||
HeI |
|
|
|
|
||
OIII |
|
6.21e-3 | 4.57e-6 |
|
|
|
OIII |
|
1.81e-2 | 3.52e-5 |
|
|
|
HeI |
|
|
|
|||
ArIII |
|
3.10e+0 | ||||
NI |
|
1.60e-5 | 4.34e-6 |
|
|
|
NI |
|
9.71e-7 | 6.59e-6 |
|
|
|
OI |
|
1.26e+0 | ||||
NII |
|
1.14e+0 | ||||
HeI25 |
|
|
|
|
||
NaI |
|
|||||
NaI |
|
|||||
OI |
|
5.63e-3 | 2.11e-5 |
|
|
|
OI |
|
1.82e-3 | 3.39e-6 |
|
|
|
NII |
|
9.84e-4 | 9.22e-7 |
|
|
|
HeII26 |
|
|||||
|
|
|
|
|
||
NII |
|
2.91e-3 | 8.65e-6 |
|
|
|
HeI |
|
|
|
|
||
SII |
|
1.39e-5 | 1.88e-4 |
|
|
|
SII |
|
5.63e-4 | 1.21e-4 |
|
|
|
HeI28 |
|
|
|
|
||
HeI |
|
|||||
ArIII |
|
3.21e-1 |
|
|
|
|
ArIV |
|
|
|
|||
ArIV |
|
4.44e-1 | 2.26e-1 | |||
ArIV |
|
4.88e-1 | 1.90e-1 | |||
HeI |
|
|||||
OII |
|
5.19e-2 |
|
|
||
OII |
|
8.37e-3 | 9.07e-2 |
|
|
|
OII |
|
9.32e-3 | 7.74e-2 |
|
|
|
OII |
|
1.49e-2 | 3.85e-2 |
|
|
|
ArIV |
|
1.22e-1 | ||||
ArIII |
|
|
|
|
|
|
ArIII |
|
|
||||
P20 |
|
|||||
P19 |
|
|||||
P18 |
|
|||||
P17 |
|
|||||
P16 |
|
|
|
|
||
P15 |
|
|
|
|
||
P14 |
|
|
|
|
||
P13 |
|
|
|
|
||
P12 |
|
|
|
|
||
SIII |
|
5.25e-6 | ||||
|
|
|
|
|||
|
|
|
|
|||
SIII |
|
1.85e-2 | 3.94e-5 |
|
|
|
HeI31 |
|
|||||
|
|
|
|
|||
SIII |
|
4.78e-2 | 2.09e-4 |
|
|
|
|
|
|
|
|||
HeI32 |
|
|||||
HeI33 |
|
|||||
|
|
|
|
The DAP performs non-parametric measurements of the emission lines using a simple moment analysis. See mangadap.proc.emissionlinemoments
and emission-line-moments
. In survey-level runs of the DAP, we have typically paired the set of moment measurements and Gaussian models; however, the number of emission-line moment measurements need not be matched to the number of emission-line Gaussian models and vice versa.
The parameters that define the emission-line moments to calculate are provided via the ~mangadap.par.emissionmomentsdb.EmissionMomentsDB
object, which is built using an SDSS-style parameter file.
The columns of the parameter file are:
Parameter | Format | Description |
---|---|---|
index |
int | Unique integer identifier of the emission line. Must be unique. |
name |
str | Name of the transition. |
lambda |
float | Rest frame wavelength of the emission line to analyze. |
waveref |
str | The reference frame of the wavelengths; must be either 'air' for air or 'vac' for vacuum. |
primary |
float[2] | A two-element vector with the starting and ending wavelength for the primary passband surrounding the emission line(s). |
blueside |
float[2] | A two-element vector with the starting and ending wavelength for a passband to the blue of the primary band. |
redside |
float[2] | A two-element vector with the starting and ending wavelength for a passband to the red of the primary band. |
and an example file might look like this:
typedef struct {
int index;
char name[6];
double lambda;
char waveref[3];
double primary[2];
double blueside[2];
double redside[2];
} DAPELB;
DAPELB 2 OIId 3728.4835 vac { 3716.3 3738.3 } { 3706.3 3716.3 } { 3738.6 3748.6 }
DAPELB 3 OII 3729.875 vac { -1 -1 } { -1 -1 } { -1 -1 }
Note in the above example that the second set of parameters define nonsensical passbands with limits of {-1 -1}
. This is used to signify that the moment parameters are "dummy" or placeholder parameters. This is used to create an empty channel in the output MAPS
file and is used just to synchronize the channel indices between the non-parametric and Gaussian-fit results. That is, it's used to ensure that, e.g., the EMLINE_SFLUX
and EMLINE_GFLUX
extensions in the datamodel-maps
.
The moment measurements are performed by ~mangadap.proc.emissionlinemoments.EmissionLineMoments
; see emission-line-moments
. A set of parameter files that define a list of emission-line moment sets are provided with the DAP source distribution and located at $MANGADAP_DIR/mangadap/data/emission_bandpass_filters
. The database you wish to use is selected by the passbands
parameter in the relevant parameter block of the plan
file. The keyword is simply the capitalized name of the file without the ".par" extension. For example, to use the elbmpl9.par database, the plan file would include
[default.eline_moments]
passbands = 'ELBMPL9'
To provide a user-defined database, simply replace the passbands
keyword with the name of the local file defining the database (in the format given above). For example,
[default.eline_moments]
passbands = '/path/to/my/local/file/my_elb_database.par'
The DAP models the emission lines using single-component Gaussian functions. See mangadap.proc.emissionlinemoments
and emission-line-modeling
. In survey-level runs of the DAP, we have typically paired the set of moment measurements and Gaussian models; however, the number of emission-line moment measurements need not be matched to the number of emission-line Gaussian models and vice versa.
The parameters that define the emission-line models to fit are provided via the ~mangadap.par.emissionlinedb.EmissionLineDB
object, which is built using an SDSS-style parameter file.
The columns of the parameter file are:
Parameter | Format | Description |
---|---|---|
index |
int | Unique integer identifier of the emission line. Must be unique. Specifically used when tying line parameters. |
name |
str | Name of the transition. |
restwave |
float | Rest frame wavelength of the emission line to analyze. |
waveref |
str | The reference frame of the wavelengths; must be either 'air' for air or 'vac' for vacuum. |
action |
str | A single character setting how the line should be treated. See emission-line-modeling-action . |
tie_f |
str[2] | A sequence of 2 10-character strings that indicate how the flux of the line should be tied to another line. The first element gives the index of the line to tie (see index above). The second element provides the constraint. Currently fluxes can only be tied by fixing the line flux ratio, and lines with tied fluxes must also have their velocity and velocity dispersions tied by equality. For example, to fix the ratio of the OIII 4959 line to the OIII 5007 line, the entry for the OIII 4959 line should be { 14 =0.34 } , where 14 is the index number of the OIII 5007 in the file and the flux in the OIII 4959 line is always 0.34 times the flux in the OIII 5007 line. |
tie_v |
str[2] | A sequence of 2 10-character strings that indicate how the velocity of the line should be tied to another line. The first element gives the index of the line to tie (see index above). The second element provides the constraint. Velocities can be tied by equality (using = ) or tied by inequality (see below); however, tying by inequality is not well tested. |
tie_s |
str[2] | A sequence of 2 10-character strings that indicate how the velocity dispersion of the line should be tied to another line. The first element gives the index of the line to tie (see index above). The second element provides the constraint. Velocity dispersions can can be tied by equality (using = ) or tied by inequality (see below). |
blueside |
float[2] | A two-element vector with the starting and ending wavelength for a passband to the blue of the primary band. |
redside |
float[2] | A two-element vector with the starting and ending wavelength for a passband to the red of the primary band. |
and an example file might look like this:
typedef struct {
int index;
char name[6];
double restwave;
char waveref[3];
char action;
char tie_f[2][10];
char tie_v[2][10];
char tie_s[2][10];
double blueside[2];
double redside[2];
} DAPEML;
DAPEML 2 OII 3727.092 vac f { None None } { 34 = } { None None } { 3706.3 3716.3 } { 3738.6 3748.6 }
DAPEML 3 OII 3729.875 vac f { None None } { 2 = } { 2 = } { 3706.3 3716.3 } { 3738.6 3748.6 }
DAPEML 23 Hb 4862.6830 vac f { None None } { 34 = } { 34 1.4 } { 4798.9 4838.9 } { 4885.6 4925.6 }
DAPEML 33 NII 6549.86 vac f { 35 =0.34 } { 35 = } { 35 = } { 6483.0 6513.0 } { 6623.0 6653.0 }
DAPEML 34 Ha 6564.608 vac f { None None } { None None } { None None } { 6483.0 6513.0 } { 6623.0 6653.0 }
DAPEML 35 NII 6585.27 vac f { None None } { 34 = } { None None } { 6483.0 6513.0 } { 6623.0 6653.0 }
Note
- Both the emission-line moments database and the emission-line modeling database define the sidebands used for the equivalent width calculations. Nominally, these should be the same, but it's up to the person that writes the two parameter files to make sure that is true.
- Format changes:
- version 3.1.0: Many parameters removed that were used by the deprecated
~mangadap.proc.elric.Elric
fitter. - version 4.1.0: Added ability to tie the three parameters to different lines; i.e., velocity can be tied to one line while dispersion is tied to a different one.
- version 3.1.0: Many parameters removed that were used by the deprecated
Line tying in the DAP uses the functionality in ppxf in a limited and abstracted way.
Tying fluxes effectively means that the lines are put in the same emission-line template. This is why, currently, any lines with tied fluxes must also tie their velocity and velocity dispersion. Also, the DAP currently does not allow tying fluxes using inequalities.
Tying kinematics can be done with equality or inequality. For equality, use the =
character, as in the example file above. Unlike the fluxes, the kinematics cannot be tied to be, e.g., a specific fraction of the value of the tied line. (I.e., you can't tie the dispersion to be exactly half of the dispersion of the tied line). For inequality, there are a couple of options:
- Use
>N
or<N
to force the value to be greater or less than the provided fraction of the the value of the tied line. E.g., to force the dispersion of one component to be at least 1.5 times larger than the tied line, use>1.5
. Using>
or<
is equivalent to>1
and<
, respectively.- To bound the value between both upper and lower limits, you must use a single fixed fractional bound. For example, setting the tied value for the dispersion to
1.4
means that the best-fitting dispersion must be greater than 1/1.4 and less than 1.4 times the dispersion of the tied line.
Warning
Although line tying has been experimented with for MaNGA data, much of the inequality tying is not well tested.
Warning
This parameter is now DEPRECATED in favor of the tie
parameter.
The moment measurements are performed by ~mangadap.proc.emissionlinemoments.EmissionLineMoments
; see emission-line-moments
. A set of parameter files that define a list of emission-line moment sets are provided with the DAP source distribution and located at $MANGADAP_DIR/mangadap/data/emission_bandpass_filters
. The database you wish to use is selected by the passbands
parameters in the relevant parameter block of the plan
file. The keyword is simply the capitalized name of the file without the ".par" extension. To provide a user-defined database, simply replace the passbands
keyword with the name of the local file defining the database (in the format given above).
The emission-line modeling is performed by ~mangadap.proc.emissionlinemodel.EmissionLineModel
; see emission-line-modeling
. A set of files that define a list of emission-line model parameter sets are provided with the DAP source distribution and located at $MANGADAP_DIR/mangadap/data/emission_lines
. The database you wish to use is selected by the emission_lines
parameter in the relevant parameter block of the plan
file. The keyword is simply the capitalized name of the file without the ".par" extension. For example, to use the elpmpl11.par database, the plan file would include
[default.eline_fits.fit]
emissionpassbands = 'ELPMPL11'
To provide a user-defined database, simply replace the passbands
keyword with the name of the local file defining the database (in the format given above). For example,
[default.eline_fits.fit]
emissionpassbands = '/path/to/my/local/file/my_elp_database.par'
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
No primary band defined because it overlaps with another line.↩
No primary band defined because it overlaps with another line.↩
No primary band defined because it overlaps with another line.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
No primary band defined because it overlaps with another line.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
No primary band defined because it overlaps with another line.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Provided magnetic dipole coefficient is actually its sum with the electric quadrupole coefficient.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
No primary band defined because it overlaps with another line.↩
No primary band defined because it overlaps with another line.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Center of gravity of the blending of fine-structure lines assuming Boltzmann populations in an optically thin plasma; see, e.g.: https://physics.nist.gov/cgi-bin/ASBib1/get_ASBib_ref.cgi?db=el&db_id=&comment_code=c69&element=H&spectr_charge=1&ref=&type=↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
No primary band defined because it overlaps with another line.↩
No primary band defined because it overlaps with another line.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩
Wavelength based on a simple average of wavelengths for many fine-structure transitions.↩