250 research outputs found
Close neighbors of Markarian galaxies. II. Statistics and discussions
According to the database from the first paper, we select 180 pairs with dV <
800 km/s and Dp < 60 kpc containing Markarian (MRK) galaxies. We study the
dependence of galaxies integral parameters, star-formation (SF) and active
galactic nuclei (AGN) properties on kinematics of pairs, their structure and
large-scale environments. Following main results were obtained: projected
radial separation Dp between galaxies correlates with the perturbation level P
of the pairs. Both parameters do not correlate with line-of-sight velocity
difference dV of galaxies. Dp and P are better measures of interaction strength
than dV. The latter correlates with the density of large-scale environment and
with the morphologies of galaxies. Both galaxies in a pair are of the same
nature, the only difference is that MRK galaxies are usually brighter than
their neighbors in average by 0.9 mag. Specific star formation rates (SSFR) of
galaxies in pairs with smaller Dp or dV is in average 0.5 dex higher than that
of galaxies in pairs with larger Dp or dV. Closeness of a neighbor with the
same and later morphological type increases the SSFR, while earlier-type
neighbors do not increase SSFR. Major interactions/mergers trigger SF and AGN
more effectively than minor ones. The fraction of AGNs is higher in more
perturbed pairs and pairs with smaller Dp. AGNs typically are in stronger
interacting systems than star-forming and passive galaxies. There are
correlations of both SSFRs and spectral properties of nuclei between pair
members.Comment: 13 pages, 8 figures, 2 table
Close pairs of galaxies with different activity levels
We selected and studied 180 pairs with dV < 800 km/s and Dp < 60 kpc
containing Markarian (MRK) galaxies to investigate the dependence of galaxies'
integral parameters, star-formation (SF) and active galactic nuclei (AGN)
properties on kinematics of pairs, their structure and large-scale
environments. Projected radial separation Dp and perturbation level P are
better measures of interaction strength than dV. The latter correlates with the
density of large-scale environment and with the morphologies of galaxies. Both
galaxies in a pair are of the same nature, the only difference is that MRK
galaxies are usually righter than their neighbors. Specific star formation
rates (SSFR) of galaxies in pairs with smaller Dp or dV is in average 0.5 dex
higher than that of galaxies in pairs with larger Dp or dV. Closeness of a
neighbor with the same and later morphological type increases the SSFR, while
earlier-type neighbors do not increase SSFR. Major interactions/mergers trigger
SF and AGN more effectively than minor ones. The fraction of AGNs is higher in
more perturbed pairs and pairs with smaller Dp. AGNs typically are in stronger
interacting systems than star-forming and passive galaxies. There are
correlations of both SSFRs and spectral properties of nuclei between pair
members.Comment: 4 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1310.024
On Orbits and Bi-invariant Subsets of Binary -Spaces
Orbits and bi-invariant subsets of binary -spaces are studied. The problem
of the distributivity of a binary action of a group on a space , which
was posed in 2016 by one of the authors, is solved.Comment: 11 page
On the Nature of Unconfirmed Supernovae
We study the nature of 39 unconfirmed supernovae (SNe) from the sky area
covered by the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8), using
available photometric and imaging data and intensive literature search. We
confirm that 21 objects are real SNe, 2 are Galactic stars, 4 are probable SNe,
and 12 remain unconfirmed events. The probable types for 4 objects are
suggested: 3 SNe are of probable type Ia, and SN 1953H is probable type II SN.
In addition, we identify the host galaxy of SN 1976N and correct the
offsets/coordinates of SNe 1958E, 1972F, and 1976N.Comment: 9 pages, 4 figures, 5 tables, published in Astrophysics (English
translation of Astrofizika
Supernovae in paired galaxies
We investigate the influence of close neighbor galaxies on the properties of
supernovae (SNe) and their host galaxies using 56 SNe located in pairs of
galaxies with different levels of star formation (SF) and nuclear activity. The
mean distance of type II SNe from nuclei of hosts is greater by about a factor
of 2 than that of type Ibc SNe. The distributions and mean distances of SNe are
consistent with previous results compiled with the larger sample. For the first
time it is shown that SNe Ibc are located in pairs with significantly smaller
difference of radial velocities between components than pairs containing SNe Ia
and II. We consider this as a result of higher star formation rate (SFR) of
these closer systems of galaxies.Comment: 2 pages. arXiv admin note: text overlap with arXiv:1312.494
Paired galaxies with different activity levels and their supernovae
We investigate the influence of close neighbor galaxies on the properties of
supernovae (SNe) and their host galaxies using 56 SNe located in pairs of
galaxies with different levels of star formation (SF) and nuclear activity. The
statistical study of SN hosts shows that there is no significant difference
between morphologies of hosts in our sample and the larger general sample of SN
hosts in the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). The mean
distance of type II SNe from nuclei of hosts is greater by about a factor of 2
than that of type Ibc SNe. The distributions and mean distances of SNe are
consistent with previous results compiled with the larger sample. For the first
time it is shown that SNe Ibc are located in pairs with significantly smaller
difference of radial velocities between components than pairs containing SNe Ia
and II. We consider this as a result of higher star formation rate (SFR) of
these closer systems of galaxies. SN types are not correlated with the
luminosity ratio of host and neighbor galaxies in pairs. The orientation of SNe
with respect to the preferred direction toward neighbor galaxy is found to be
isotropic and independent of kinematical properties of the galaxy pair.Comment: 10 pages, 2 figures, 5 tables, online data, published in Astrophysics
and Space Scienc
Supernovae and their host galaxies - IV. The distribution of supernovae relative to spiral arms
Using a sample of 215 supernovae (SNe), we analyze their positions relative
to the spiral arms of their host galaxies, distinguishing grand-design (GD)
spirals from non-GD (NGD) galaxies. We find that: (1) in GD galaxies, an offset
exists between the positions of Ia and core-collapse (CC) SNe relative to the
peaks of arms, while in NGD galaxies the positions show no such shifts; (2) in
GD galaxies, the positions of CC SNe relative to the peaks of arms are
correlated with the radial distance from the galaxy nucleus. Inside (outside)
the corotation radius, CC SNe are found closer to the inner (outer) edge. No
such correlation is observed for SNe in NGD galaxies nor for SNe Ia in either
galaxy class; (3) in GD galaxies, SNe Ibc occur closer to the leading edges of
the arms than do SNe II, while in NGD galaxies they are more concentrated
towards the peaks of arms. In both samples of hosts, the distributions of SNe
Ia relative to the arms have broader wings. These observations suggest that
shocks in spiral arms of GD galaxies trigger star formation in the leading
edges of arms affecting the distributions of CC SNe (known to have short-lived
progenitors). The closer locations of SNe Ibc vs. SNe II relative to the
leading edges of the arms supports the belief that SNe Ibc have more massive
progenitors. SNe Ia having less massive and older progenitors, have more time
to drift away from the leading edge of the spiral arms.Comment: 19 pages, 10 figures, 11 tables, resubmitted to MNRAS after
addressing referee's comment
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