J/A+A/712/A89 NGC 891 CO(1-0) datacubes (Jimenez-Lopez+, 2026)
Imaging the disk-halo interface of NGC 891: A 2.7 kpc-thick molecular gas disk.
Jimenez-Lopez D., Garcia-Burillo S., Querejeta M., Usero A., Tarrio P.
<Astron. Astrophys. 712, A89 (2026)>
=2026A&A...712A..89J 2026A&A...712A..89J (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Galaxies, nearby ; Carbon monoxide
Keywords: galaxies: halos - galaxies: ISM - galaxies: individual: NGC 891 -
galaxies: spiral - galaxies: structure - radio lines: galaxies
Abstract:
Halos surrounding spiral galaxies act as the bridges connecting the
galactic dis k and the intergalactic medium (IGM). They host a
significant fraction of the baryonic mass in the Universe, and
feedback from star formation (SF) or active galactic nuclei (AGN)
likely plays an important role in regulating this vertical baryonic
component. Despite its importance, the contribution of extraplanar
molecular gas remains poorly understood.
We aim to characterize the vertical extent and the kinematics of
molecular gas traced by CO(2-1) emission in the nearby (D=9.5Mpc)
spiral galaxy NGC891, one of the best studied edge-on galaxies. We
also compare our results with the extr aplanar distribution of other
tracers of baryonic matter, including atomic gas (HI), diffuse
ionized gas (Hα-traced DIG), and dust maps from the literature.
Our analysis is based on new CO(2-1) observations of NGC 891
obtained with the IRAM 30m telescope. We mapped two 6kpcx6kpc
regions on the northeastern side and the area surrounding the galactic
center. We apply a careful method to estimate and remove the residual
contribution of the error beam to the CO cube.
The vertical extent of the molecular gas is best described by a
two-component Gaussian fit, consisting of a bright thin disk component
(deconvolved FWHM≤360pc; upper limit) and a fainter thick disk
component (deconvolved FWHM≃1.1kpc). Statistically significant
(>3σ) CO(2-1) emission is detected up to 1.3-1.4kpc above the
disk midplane. We estimate that the thick molecular disk component
contains up to ∼27% of the total molecular gas mass of the galaxy.
The vertical extent of Hα emission is similar to that of the
molecular gas, whereas HI extends much further.
Our results demonstrate that SF-driven feedback in a non-starburst
galaxy can lift significant amounts of molecular gas to large vertical
distances. We interpret the presence of extraplanar molecular gas in
NGC 891 in the framework of a galactic fountain scenario, in which
material is expelled from star-forming regions and transported toward
the outer halo. This is supported by optical images where dust columns
rise from the inner disk, showing spatial correlation between CO(2-1),
Hα, and dust.
Description:
We present the 3D data cube of the CO(2-1) emission of NGC 891 used in
this work (2 spatial dimensions + 1 spectral dimension). The object
was observed with the IRAM 30m telescope. We also include the three
moment maps studied in this paper, derived from the data cube using
the Spectral-Cube Python library.
Objects:
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RA (2000) DE Designation(s)
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02 22 32.90 +42 20 53.9 NGC 891 = MCG+07-05-046
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Description of file: NGC891cubeCO.fits
3D FITS data cube of the CO(2-1) emission of NGC 891, observed with
the IRAM 30m telescope. The science-ready cube has been fully
calibrated, cleaned, and reprojected onto a regular spatial and
spectral grid.
Dimensions of the cube: (132 x 102 x 115) (RA-SIN, DEC-SIN, VRAD).
Pixel scale: 2 arcsec/pixel.
Velocity channel width of 10.4 km/s.
Relevant FITS keywords:
OBJECT = NGC 891
LINE = CO(2-1)
RESTFREQ = 230.538 GHz
BUNIT = K (Ta*)
BMAJ/BMIN = 11.25 arcsec
Description of file: NGC891_M0.fits, NGC891_M1.fits, NGC891_M2.fits
2D FITS images of the moment maps, derived from the CO(2-1) data cube.
Moment maps are obtained using the Spectral-Cube python library
(https://spectral-cube.readthedocs.io/en/latest/)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 136 4 List of fits images and datacube
fits/* . 4 Individual fits images and datacube
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See also:
J/A+A/565/A4 : NGC 891 70-500um images (Hughes+, 2014)
J/A+A/575/A17 : NGC 891 Herschel PACS and SPIRE spectroscopy (Hughes+, 2015)
J/A+A/615/A98 : NGC 891 LOFAR and AMI maps (Mulcahy+, 2018)
J/A+A/632/A12 : NGC 891 and NGC 4565 radio images (Schmidt+, 2019)
J/ApJ/832/118 : Emission-line spectroscopy in NGC 891 (Boettcher+, 2016)
J/ApJ/853/114 : Vertical population gradients in NGC 891. I.
(Eigenbrot+, 2018)
J/ApJ/895/71 : 8um Cores in NGC 891, NGC 3628 & IC 5052 (Elmegreen+, 2020)
J/MNRAS/396/1231 : Astrophotometric catalogue of NGC 891 (Rejkuba+, 2009)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20 I1 arcsec/pix scale ? Scale of the image, for the datacube
22- 24 I3 --- Nx Number of pixels along X-axis
26- 28 I3 --- Ny Number of pixels along Y-axis
30- 32 I3 --- Nz ? Number of slices, for the datacube
34- 41 F8.1 m/s bVRAD ? Lower value of VRAD interval, for the datcube
43- 53 E11.6 m/s BVRAD ? Upper value of VRAD interval, for the datcube
55- 61 F7.1 m/s dVRAD ? VRAD resolution
63- 66 I4 Kibyte size Size of FITS file
68- 86 A19 --- FileName Name of FITS file, in subdirectory fits
88-136 A49 --- Title Title of the FITS file
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Acknowledgements:
Daniel Jimenez-Lopez, d.jimenez(at)oan.es
License: CC-BY-4.0
(End) Patricia Vannier [CDS] 07-Jun-2026