J/A+A/710/A412 PHANGS-Halpha nearby star-forming galaxies (Razza+, 2026)
The PHANGS-Halpha survey. Ground-based narrow-band imaging of
nearby star-forming galaxies.
Razza A., Blanc G.A., Groves B., Congiu E., Neumann J., Pan H.-A., Ho I-T.,
Barnes A.T., Belfiore F., Boquien M., Burton C., Chevance M., Egorov O.,
Emsellem E., Faesi C., Glover S.C.O., Grasha K., Klessen R.S., Kreckel K.,
Leroy A.K., McElroy R., Pessa I., Schinnerer E., Tomicic N., Amiri A.,
Anand G.S., Cao Y., Dale D.A., Dlamini S., Li J., Mendez-Delgado J.E.,
Murphy E.J., Pathak D., Querejeta M., Ramambason L., Rosolowsky E.,
Scheuermann F., Ubeda L., Williams T.G.
<Astron. Astrophys. 710, A412 (2026)>
=2026A&A...710A.412R 2026A&A...710A.412R (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Photometry, H-alpha ;
Keywords: galaxies: ISM - galaxies: photometry - galaxies: spiral -
galaxies: star formation
Abstract:
We present PHANGS-Hα, a narrowband imaging survey that maps
Hα emission over a sample of 65 nearby massive star-forming
galaxies. The data were obtained using the MPG-ESO 2.2-meter telescope
at La Silla and the du Pont 2.5-meter telescope at Las Campanas
Observatory, within the framework of the multi-wavelength cloud-scale
(50-100pc) resolution mapping of molecular gas and star formation
conducted by the Physics at High Angular resolution in Nearby GalaxieS
(PHANGS) collaboration. PHANGS-Hα complements the published
PHANGS-ALMA, PHANGS-MUSE, PHANGS-HST, and PHANGS-JWST surveys,
providing an anchor point for the photometric and astrometric
calibration of these datasets, as well as samples of HII regions and
star formation rate maps for the bulk of the PHANGS sample. We
describe the observations, data processing, and calibration of the
PHANGS-Hα dataset, as well as the procedures used to derive
emission-line fluxes from narrowband imaging. A subset of galaxies
with available spectroscopic Ha mapping from the PHANGS-MUSE survey
serves as the basis of a detailed comparison with the narrowband
photometry presented here. This comparison informs a set of best
practices for the processing of narrowband Hα imaging, which we
subsequently apply to the full dataset.
Description:
This catalog presents the global properties and observational
parameters of the PHANGS-Hα galaxy sample. It includes galaxy
properties and derived quantities from Hα imaging.
Two tables list all PHANGS-Hα survey targets observed with the
MPG 2.2m and du Pont 2.5m telescopes at La Silla and Las Campanas
observatories, respectively. Three galaxies were observed with both
telescopes. The first table provides global properties of the galaxy
sample such as positions, distances, structural parameters, stellar
masses, and star formation rates, compiled from the literature. The
second table reports observational parameters and derived quantities
from Hα imaging, including sensitivity limits, [NII]
contamination estimates, filter transmission corrections, and
integrated Hα luminosities. The [NII] contamination fraction
and filter transmission are used to derive Hα emission-line maps
from broad-band (R) and narrow-band (Hα) imaging.
Spectroscopically derived [NII]-to-Hα fractions based on the
subset of 19 galaxies in common with PHANGS-MUSE (flagged in the first
table) are presented and discussed in the associated paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablef1.dat 92 65 Global properties of the PHANGS-Hα sample
tablef2.dat 81 68 Observational parameters and derived quantities
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See also:
J/ApJS/219/4 : S4G pipeline 4: multi-component decompositions (Salo+, 2015)
J/ApJ/897/122 : Rotational velocities for PHANGS sample of galaxies
(Lang+, 2020)
J/ApJS/257/43 : PHANGS-ALMA: arcsecond CO(2-1) imaging of galaxies
(Leroy+, 2021)
Byte-by-byte Description of file: tablef1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Galaxy Galaxy name
10- 23 A14 --- Tel Telescope(s) used
25- 28 A4 --- Type Morphological T-type (LEDA)
30- 31 I2 h RAh Right Ascension (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
33- 34 I2 min RAm Right Ascension (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
36- 39 F4.1 s RAs Right Ascension (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
41 A1 --- DE- Declination sign (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
42- 43 I2 deg DEd Declination (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
45- 46 I2 arcmin DEm Declination (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
48- 51 F4.1 arcsec DEs Declination (J2000) (S4G, Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S, Cat. J/ApJS/219/4)
53- 57 F5.2 Mpc Dist Distance (Anand et al.,
2021MNRAS.501.3621A 2021MNRAS.501.3621A)
59- 62 I4 km/s RV Radial velocity (Lang et al.,
2020ApJ...897..122L 2020ApJ...897..122L, Cat. J/ApJ/897/122)
64- 66 I3 arcsec R25 Isophotal radius (HyperLEDA)
68- 71 F4.1 deg Incl Inclination (Lang et al.,
2020ApJ...897..122L 2020ApJ...897..122L, Cat. J/ApJ/897/122)
73- 78 F6.1 deg PA [] Position Angle (Lang et al.,
2020ApJ...897..122L 2020ApJ...897..122L, Cat. J/ApJ/897/122)
80- 84 F5.2 10+10Msun Mstar Stellar mass (Leroy et al.,
2021ApJS..257...43L 2021ApJS..257...43L, cat. J/ApJS/257/43)
86- 90 F5.2 Msun/yr SFR Star Formation Rate (Leroy et al.,
2021ApJS..257...43L 2021ApJS..257...43L, cat. J/ApJS/257/43)
92 I1 --- PHANGS-MUSE [0/1] Flag: 1 if PHANGS-MUSE overlap
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Byte-by-byte Description of file: tablef2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Galaxy Galaxy name
10- 11 A2 --- BBFil Broad-band filter name
13- 16 I4 s BBExp Broad-band integration time
18- 22 F5.2 mag/arcsec2 BBLim Broad-band 3-sigma surface brightness
sensitivity
24- 27 F4.2 arcsec BBResA Broad-band PSF FWHM in arcsec
29- 31 I3 pc BBResP Broad-band PSF FWHM in parsec
33- 37 A5 --- NBFil Narrow-band filter name
39- 43 I5 s NBExp Narrow-band Integration time
45- 49 F5.2 mag/arcsec2 NBLim Narrow-band 3-sigma surface brightness
sensitivity
51- 54 F4.2 arcsec NBResA Narrow-band PSF FWHM in arcsec
56- 58 I3 pc NBResP Narrow-band PSF FWHM in parsec
60- 63 F4.2 10-19W/m2/arcsec2 HaLim H-alpha 3-sigma surface brightness
sensitivity in
10-16erg/s/cm2/arcsec2 unit
65- 69 F5.3 --- FNII [0.16/0.47] [NII]/H-alpha fraction (1)
71- 75 F5.3 --- THa H-alpha effective filter transmission
77- 81 F5.2 [10-7W] logLHa Integrated H-alpha luminosity in
log(erg/s) unit (2)
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Note (1): FNII values listed in this table are defined as (Eq. 5 in the paper)
[NII]6548+[NII]6583)/(Hα6562+[NII]6548+[NII]6583).
These fractions, together with the effective filter transmissions THa
are used to derive the H-alpha emission maps (Eq. 6 in the paper).
These measurements are superseded by the spectroscopically calibrated
values discussed in the paper, Sect. 6. They are provided for
completeness and reproducibility of the analysis.
Note (2): H-alpha luminosities are corrected for Galactic extinction only.
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Acknowledgements:
Alessandro Razza, alessandro.razza0(at)gmail.com
License: CC-BY-4.0
(End) Patricia Vannier [CDS] 30-Apr-2026