TY - JOUR

T1 - Spectral Observations of Superthin Galaxies

AU - Bizyaev, D.V.

AU - Макаров, Д.И.

AU - Решетников, Владимир Петрович

AU - Мосенков, Александр Владимирович

AU - Kautsch, S.J.

AU - Антипова, Александра

PY - 2021/6/20

Y1 - 2021/6/20

N2 - We conduct spectral observations of 138 superthin galaxies (STGs) with high radial-to-vertical stellar disk scale ratios with the Dual Imaging Spectrograph on the 3.5 m telescope at the Apache Point Observatory (APO) to obtain the ionized gas rotation curves with R ~5000 resolution. We also performed near-infrared (NIR) H and Ks photometry for 18 galaxies with the NICFPS camera on the 3.5 m telescope. The spectra, the NIR photometry, and published optical and NIR photometry are used for modeling that utilizes the thickness of the stellar disk and rotation curves simultaneously. The projection and dust extinction effects are taken into account. We evaluate eight models that differ in their free parameters and constraints. As a result, we estimated the masses and scale lengths of the galactic dark halos. We find systematic differences between the properties of our red and blue STGs. The blue STGs have a large fraction of dynamically underevolved galaxies whose vertical velocity dispersion is low in both gas and stellar disks. The dark halo-to-disk scale ratio is shorter in the red STGs than in the blue ones, but in a majority of all STGs, this ratio is under 2. The optical color (r − i) of the STGs correlates with their rotation curve maximum, vertical velocity dispersion in stellar disks, and mass of the dark halo. We conclude that there is a threshold central surface density of 50 M⊙ pc−2 below which we do not observe very thin, rotationally supported galactic disks.

AB - We conduct spectral observations of 138 superthin galaxies (STGs) with high radial-to-vertical stellar disk scale ratios with the Dual Imaging Spectrograph on the 3.5 m telescope at the Apache Point Observatory (APO) to obtain the ionized gas rotation curves with R ~5000 resolution. We also performed near-infrared (NIR) H and Ks photometry for 18 galaxies with the NICFPS camera on the 3.5 m telescope. The spectra, the NIR photometry, and published optical and NIR photometry are used for modeling that utilizes the thickness of the stellar disk and rotation curves simultaneously. The projection and dust extinction effects are taken into account. We evaluate eight models that differ in their free parameters and constraints. As a result, we estimated the masses and scale lengths of the galactic dark halos. We find systematic differences between the properties of our red and blue STGs. The blue STGs have a large fraction of dynamically underevolved galaxies whose vertical velocity dispersion is low in both gas and stellar disks. The dark halo-to-disk scale ratio is shorter in the red STGs than in the blue ones, but in a majority of all STGs, this ratio is under 2. The optical color (r − i) of the STGs correlates with their rotation curve maximum, vertical velocity dispersion in stellar disks, and mass of the dark halo. We conclude that there is a threshold central surface density of 50 M⊙ pc−2 below which we do not observe very thin, rotationally supported galactic disks.

KW - 3-DIMENSIONAL DISTRIBUTION

KW - DARK-MATTER HALO

KW - DISK COLOR GRADIENTS

KW - EDGE-ON

KW - HI IMAGING OBSERVATIONS

KW - ON SPIRAL GALAXIES

KW - ROTATION CURVES

KW - STELLAR DISKS

KW - STRUCTURAL PARAMETERS

KW - SURFACE BRIGHTNESS GALAXIES

UR - http://www.scopus.com/inward/record.url?scp=85109045994&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/d36fd0fd-b60d-327b-a4ed-68c579d72cb3/

U2 - 10.3847/1538-4357/abfb03

DO - 10.3847/1538-4357/abfb03

M3 - Article

VL - 914

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 104

ER -