J/A+A/702/A42 NGC 3259 spectroscopic dataset (Grishin+, 2025)
NGC 3259: A signal for an untapped population of slowly accreting
intermediate-mass black holes.
Grishin K.A., Chilingarian I.V., Combes F., Bauer F.E., Toptun V.A.,
Katkov I.Yu., Fabricant D., Kolganov F., Graham A.W.
<Astron. Astrophys. 702, A42 (2025)>
=2025A&A...702A..42G 2025A&A...702A..42G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert ; Galaxies, spectra ; Optical ; Infrared
Keywords: galaxies: active - galaxies: bulges - galaxies: individual: NGC3259 -
galaxies: nuclei - galaxies: Seyfert
Abstract:
Low-mass active galactic nuclei (AGNs) can provide important
constraints on the formation and evolution of supermassive black holes
(SMBHs), which stands as a central challenge in modern cosmology. To
date, only small samples of intermediate-mass black holes (IMBHs,
M(BH)<105M☉) and "lesser" SMBHs (LSMBHs, M(BH)<106M☉)
have been identified. Our present study of NGC 3259 at D=27 Mpc with
the Binospec integral field unit (IFU) spectrograph complemented with
Keck Echelle Spectrograph and Imager observations demonstrates the
strong capability and necessity for spectroscopic follow-up studies.
NGC 3259 hosts a black hole (BH) with a mass of
M(BH)=(2.0-4.9)*105M☉ from multi-epoch spectroscopic data,
which is accreting at 1% of the Eddington limit, as suggested by the
analysis of archival XMM-Newton observations. It is the second-nearest
broad-line low-mass AGN after the archetypal galaxy NGC 4395. The
spectroscopic data reveal a variable broad Ha profile likely resulting
from asymmetrically distributed broad-line region (BLR) clouds or BLR
outflow events. X-ray observations and the absence of an optical
power-law continuum suggest partial obscuration of the accretion disk
and hot corona by a dust torus. We estimated that Sloan Digital Sky
Survey (SDSS) observations would only have the capacity to detect
similar objects up to D=35Mpc. A detailed photometric analysis of NGC
3259 using HST images provides a central spheroid stellar mass
estimate that is 20 times lower than expected, based on the M(BH) -
M(sph) relation, making this galaxy a significant outlier. This
discrepancy suggests divergent growth pathways for the central BH and
spheroid, potentially influenced by the potential presence of a bar in
the galaxy. Finally, we demonstrate that the DESI and 4MOST surveys
will detect low-accretion-rate IMBHs and LSMBHs, while the sensitivity
of future X-ray instruments (such as AXIS and Athena) will secure
their classification.
Description:
A spectroscopic dataset for NGC 3259 presented in the paper.
This dataset includes reduced long-slit, echelle and IFU spectra,
obtained for NGC 3259.
Objects:
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RA (2000) DE Designation(s)
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10 32 34.86 +65 02 27.9 NGC 3259 = QSO J1032+6502
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 202 5 List of fits files
fits/* . 5 Individual fits files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Righ ascension (J2000)
4- 5 I2 min RAm Righ ascension (J2000)
7- 11 F5.2 s RAs Righ ascension (J2000)
12 A1 --- DE- Declination sign (J2000)
13- 14 I2 deg DEd Declination (J2000)
16- 17 I2 arcmin DEm Declination (J2000)
19- 22 F4.1 arcsec DEs Declination (J2000)
24- 28 I5 --- Nx Number of pixels along X-axis
30- 33 I4 --- Ny Number of pixels along Y-axis
35- 56 A22 "datime" Obs.date Observation date
58- 64 F7.2 0.1nm bAWAV Lower value of wavelength interval
66- 73 F8.2 0.1nm BAWAV Upper value of wavelength interval
75- 79 F5.3 0.1nm dAWAV Wavelength resolution
81- 85 I5 Kibyte size Size of FITS file
87-132 A46 --- FileName Name of FITS file, in subdirectory fits
134-202 A69 --- Title Title of the FITS file
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Acknowledgements:
Kirill Grishin, kirillg6(at)gmail.com
(End) Patricia Vannier [CDS] 10-Sep-2025