J/MNRAS/542/3315 Infrared and optical emission-line diagnostics (Durre, 2025)
Infrared and optical emission-line diagnostics.
Durre M.
<Mon. Not. R. Astron. Soc. 542, 3315-3330 (2025)>
=2025MNRAS.542.3315D 2025MNRAS.542.3315D (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert ; Galaxies, spectra ; Galaxies, IR ;
Galaxies, optical; Galaxy catalogs
Keywords: techniques: spectroscopic - galaxies: active -
quasar: emission lines - galaxies: Seyfert - galaxies: statistics
Abstract:
We study a catalogue of over 130 emission-line galaxies with matched
near infra-red (NIR) and optical spectra, where we examine the
relationship between the respective nuclear activity classifications,
diagnosed by the flux ratios of emission lines. We match the standard
NIR classification with four different optical classifications. While
there is a broad agreement between the two regimes, there are
mismatches and overlaps caused either by aperture effects and/or NIR
radiation penetrating obscuring dust and "seeing deeper" into the
nuclear region, thus exposing AGN activity. We examine the
relationship between the equivalent widths (EW) of Hα and
Paβ, as well as the ratios [NII]/Hα vs. [FeII]/Paβ,
and find reasonable correlations. We thus propose a new diagnostic (EW
of Pa beta with Fe-WPF) in the NIR (analogous to the WHaN
classification), using the [FeII]/Paβ flux ratio and the EW of
the Paβ line. We show, within the limitations of the catalogue
size, that the regions of the standard NIR diagram can be reasonably
replicated in this new scheme. This diagnostic has the advantage that
only one wavelength range needs to be observed, thus being economical
with telescope time.
Description:
We have studied a catalogue of 132 emission-line galaxies (combined
from the catalogues of Riffel et al., 2021MNRAS.503.5161R 2021MNRAS.503.5161R; Mason et
al., 2015ApJS..217...13M 2015ApJS..217...13M; Durre et al., 2023MNRAS.524.4923D 2023MNRAS.524.4923D, Cat.
J/MNRAS/524/4923; Martins et al., 2013MNRAS.431.1823M 2013MNRAS.431.1823M) with matched
NIR and optical spectra, to examine the relationship between the
respective activity classifications, which are deduced by ratios of
the fluxes of emission lines.
We compare the standard NIR classification (Larkin et al.,
1998ApJS..114...59L 1998ApJS..114...59L; Rodriguez-Ardila et al., 2005MNRAS.364.1041R 2005MNRAS.364.1041R;
Riffel et al., 2013MNRAS.430.2002R 2013MNRAS.430.2002R, 2021MNRAS.503.5161R 2021MNRAS.503.5161R) with three
optical classifications (Kewley et al. 2001ApJ...556..121K 2001ApJ...556..121K; Kauffmann
et al. 2003MNRAS.346.1055K 2003MNRAS.346.1055K; Stasinska et al. 2006MNRAS.371..972S 2006MNRAS.371..972S) plus
the WHaN classification of Cid Fernandes et al. (2010MNRAS.403.1036C 2010MNRAS.403.1036C,
2011MNRAS.413.1687C 2011MNRAS.413.1687C).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 149 132 Infrared and optical emission line flux ratios
with activity classifications
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Object Object ID
24 I1 --- CatalogIR NIR Catalog number (1)
26- 30 F5.2 [-] log(Fe/Pab) Log [FeII]/Paβ line flux ratio
32- 35 F4.2 [-] e_log(Fe/Pab) Log [FeII]/Paβ line flux ratio
uncertainty
37- 41 F5.2 [-] log(H2/Brg) Log H2/Brγ line flux ratio
43- 46 F4.2 [-] e_log(H2/Brg) Log H2/Brγ line flux ratio
uncertainty
48- 52 F5.2 [nm] log(EWPab) Log Equivalent width of Paβ
54- 57 F4.2 [nm] e_log(EWPab) Log Equivalent width of Paβ
uncertainty
59- 60 A2 --- IRULFlag Flag for upper limits (5)
62- 68 A7 --- NIRType NIR activity type (6)
70- 72 A3 --- WPFType WPF activity type (6)
74- 78 A5 --- NIRFlag Flags on NIR measurements (2)
80- 81 I2 --- CatalogOpt Optical Catalog No. (3)
83- 87 F5.2 [-] log(NII/Ha) ? Log [NII]/Hα line flux ratio
89- 92 F4.2 [-] e_log(NII/Ha) ? Log [NII]/Hα line flux ratio
uncertainty
94- 98 F5.2 [-] log(SII/Ha) ? Log [SII]/Hα line flux ratio
100-103 F4.2 [-] e_log(SII/Ha) ? Log [SII]/Hα line flux ratio
uncertainty
105-109 F5.2 [-] log(OIII/Hb) ? Log [OIII]/Hβ line flux ratio
111-114 F4.2 [-] e_log(OIII/Hb) ? Log [OIII]/Hβ line flux ratio
uncertainty
116-120 F5.2 [nm] log(EWHa) ? Log Equivalent width of Hα
122-125 F4.2 [nm] e_log(EWHa) ? Log Equivalent width of Hα
uncertainty
127-130 A4 --- OptTypeKK Optical activity type - Kewley/Kaufmann (6)
132-134 A3 --- OptTypeSII Optical activity type -
SII (as for Kewley/Kaufmann without COMP)
136-138 A3 --- OptTypeS06 Optical activity type - S06
140-143 A4 --- OptTypeWHaN Optical activity type - WHaN
145-149 A5 --- OptFlag Flags on optical measurements (4)
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Note (1): NIR Catalog Reference as follows:
1 = Riffel et al., 2021MNRAS.503.5161R 2021MNRAS.503.5161R
2 = Mason et al., 2015ApJS..217...13M 2015ApJS..217...13M
3 = Mould et al., 2012ApJS..203...14M 2012ApJS..203...14M,
Durre et al., 2023MNRAS.524.4923D 2023MNRAS.524.4923D, Cat. J/MNRAS/524/4923
4 = Martins et al., 2013MNRAS.431.1823M 2013MNRAS.431.1823M
Note (2): NIR Measurement Flag as follows:
1 = Broad hydrogen lines modelled with two components.
2 = Broad hydrogen lines modelled with Lorentzian curve.
3 = No Brγ measurement, ratio from Paβ used.
4 = No hydrogen lines (Paβ or Brγ), upper limits used.
5 = Hydrogen line fits uncertain, due to noise or multiple components.
6 = Outflows, modelled with 2 Gaussian curves.
Note (3): Opt Catalog Reference as follows:
0 = No data or reference
1 = jones et al., 2004MNRAS.355..747J 2004MNRAS.355..747J
2 = Oh et al., 2022ApJS..261....4O 2022ApJS..261....4O, Cat. J/ApJS/261/4
3 = Ho et al., 1995ApJS...98..477H 1995ApJS...98..477H, Cat. J/ApJS/98/477
4 = Abdurro'uf et al., 2022ApJS..259...35A 2022ApJS..259...35A, Cat. III/286
5 = van den Bosch et al., 2015ApJS..218...10V 2015ApJS..218...10V, Cat. J/ApJS/218/10
6 = CfA Archive, https://oirsa.cfa.harvard.edu/search/
7 = Moustakas & Kennicutt, 2006ApJS..164...81M 2006ApJS..164...81MKENNICUTT
8 = NOIRLab Archive, https://astroarchive.noirlab.edu/portal/search/
9 = Kennicutt, 1992ApJS...79..255K 1992ApJS...79..255K, Cat. VII/141
10 = Falco et al., 1999PASP..111..438F 1999PASP..111..438F, Cat. J/PASP/111/438
11 = Ohyama et al., 1997ApJ...480L...9O 1997ApJ...480L...9O
12 = Shuder & Osterbrock, 1981ApJ...250...55S 1981ApJ...250...55S
13 = Kewley et al., 2001ApJS..132...37K 2001ApJS..132...37K
14 = Moran et al., 2000ApJ...540L..73M 2000ApJ...540L..73M
15 = Menezes et al., 2022MNRAS.513.5935M 2022MNRAS.513.5935M
Note (4): Opt Measurement Flag as follows:
1 = Broad hydrogen lines, fitted with two components.
2 = No Hβ measurement, ratio from H alpha used.
3 = No [OIII] measurement.
4 = [SII] outside of spectral range or no [SII] flux measurable
5 = No blue spectrum available.
6 = [OIII]5007Å out of spectral range, ratio from [OIII]4959Å used.
7 = Spectrum too noisy
8 = Flux values acquired from tabular data.
9 = Digitised plots from the reference source paper.
Note (5): Flag as follows:
> = Paβ and Brγ upper limits
≫ = No Brγ, computed frpm Paβ value.
Note (6): activity type as follows
SF = star forming
AGN = active galactic nucleus
HLR = high line ratio
HLR(UL) = HLR with Paβ or Brγ upper limits
COMP = composite
SEY = Seyfert
LIN = LINER
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Acknowledgements:
Mark Durre, mdurre(at)swin.edu.au
(End) Patricia Vannier [CDS] 19-Aug-2025