pinecone/core-2020-05-10-deduplication huggingface dataset:
GPS/CSS radio sources and their relation to other AGN

We are entering a new era of sensitive, large-area and multi-frequency radio
surveys that will allow us to identify Gigahertz-Peaked Spectrum (GPS) and
Compact Steep Spectrum (CSS) radio sources over a wide range in radio
luminosity and study them within the context of the overall radio-source
populations to which they belong. 'Classical' GPS/CSS objects are extremely
luminous radio sources with a compact double morphology, commonly thought to
represent the earliest stages in the life cycle of powerful radio galaxies
(e.g. O'Dea 1998). It is now becoming easier to identify GPS/CSS candidates
with much lower radio luminosity - particularly in the nearby Universe. These
less powerful objects, with typical 1.4 GHz radio luminosities of $10^{23}$ to
$10^{25}$ W/Hz, include peaked-spectrum radio sources with a core-jet
morphology on parsec scales as well as high-frequency GPS-like peaked
components embedded within lower-frequency extended emission. In the latter
case, the presence of a young GPS component may not be evident from
low-frequency data alone. Many radio galaxies in the local Universe have a
compact (FR-0) morphology, and appear to lack extended radio emission on
kiloparsec scales. The relationship of these FR-0 objects to the classical
GPS/CSS radio sources remains unclear - some of them may represent short-lived
episodes of AGN activity that will not lead to an extended FR-1 or FR-2 radio
galaxy. Future wide-band radio surveys will shed more light on this - such
surveys should ideally be coordinated to cover the full frequency range from
100 MHz to 100 GHz in order to sample all stages of GPS/CSS evolution in an
unbiased way.Comment: 9 pages, 11 figures, 1 table. Accepted for publication in
  Astronomische Nachrichten. Review presented at the 5th Workshop on CSS and
  GPS radio sources, held in Rimini (Italy) in May 201
The new class of FR0 radio galaxies

Are the FRI and FRII radio galaxies representative of the radio-loud (RL) AGN
population in the local Universe? Recent studies on the local low-luminosity
radio sources cast lights on an emerging population of compact radio galaxies
which lack extended radio emission. In a pilot JVLA project, we study the
high-resolution images of a small but representative sample of this population.
The radio maps reveal compact unresolved or slightly resolved radio structures
on a scale of 1-3 kpc. We find that these RL AGN live in red massive early-type
galaxies, with large black hole masses ($\gtrsim$10$^{8}$ M$_{\odot}$), and
spectroscopically classified as Low Excitation Galaxies, all characteristics
typical of FRI radio galaxies which they also share the same nuclear luminosity
with. However, they are more core dominated (by a factor of $\sim$30) than FRIs
and show a clear deficit of extended radio emission. We call these sources
'FR0' to emphasize their lack of prominent extended radio emission. A
posteriori, other compact radio sources found in the literature fulfill the
requirements for a FR0 classification. Hence, the emerging FR0 population
appears to be the dominant radio class of the local Universe. Considering their
properties we speculate on their possible origins and the possible cosmological
scenarios they imply.Comment: 5 pages, 3 figures. Submitted for publication in Astronomische
  Nachrichten. Contribution to the proceedings of the 5th Workshop on CSS and
  GPS radio sources, held in Rimini (Italy) in May 201
The Lockman Hole with LOFAR - Searching for GPS and CSS sources at low
  frequencies

The Lockman Hole Project is a wide international collaboration aimed at
exploiting the multi-band extensive and deep information available for the
Lockman Hole region, with the aim of better characterizing the physical and
evolutionary properties of the various source populations detected in deep
radio fields. Recent observations with the LOw-Frequency ARray (LOFAR) extends
the multi-frequency radio information currently available for the Lockman Hole
(from 350 MHz up to 15 GHz) down to 150 MHz, allowing us to explore a new radio
spectral window for the faint radio source population. These LOFAR observations
allow us to study the population of sources with spectral peaks at lower radio
frequencies, providing insight into the evolution of GPS and CSS sources. In
this general framework, I present preliminary results from 150 MHz LOFAR
observations of the Lockman Hole field.Comment: Proceedings of the "5th Workshop on Compact Steep Spectrum and
  GHz-peaked Spectrum Radio Sources". To be published in Astronomische
  Nachrichten (6 pages
Cold gas and the disruptive effect of a young radio jet

Newly born and young radio sources are in a delicate phase of their life.
Their jets are fighting their way through the surrounding gaseous medium,
strongly experiencing this interaction while, at the same time, impacting and
affecting the interstellar medium (ISM). Here we present the results from two
studies of HI (in absorption) and molecular gas illustrating what can be
learned from these phases of the gas. We first describe a statistical study
with the WSRT. The study shows that the young radio sources not only have an
higher detection rate of HI, but also systematically broader and more
asymmetric HI profiles, most of them blueshifted. This supports the idea that
we are looking at young radio jets making their way through the surrounding
ISM, which also appears to be, on average, richer in gas than in evolved radio
sources. Signatures of the impact of the jet are seen in the kinematics of the
gas. However, even among the young sources, we identify a population that
remains undetected in HI even after stacking their profiles. Orientation
effects can only partly explain the result. These objects either are genuinely
gas-poor or have different conditions of the medium, e.g. higher spin
temperature. We further present the ALMA study of molecular gas in IC5063 to
trace in detail the jet impacting the ISM. The kinematics of the cold,
molecular gas co-spatial with the radio plasma shows this process in action.
The ALMA data reveal a fast outflow of molecular gas extending along the entire
radio jet (~1 kpc), with the highest outflow velocities at the location of the
brighter hot-spot. We propose a scenario where the radio jet is expanding into
a clumpy medium, interacting directly with the clouds and inflating a cocoon
that drives a lateral outflow into the ISM.Comment: Proceedings of the "5th Workshop on Compact Steep Spectrum and
  GHz-peaked Spectrum Radio Sources". To be published in Astronomische
  Nachrichten (6 pages, 6 figures
N_H - N_HI correlation in Gigahertz-peaked-spectrum galaxies

With the Westerbork Synthesis Radio Telescope, we performed HI observations
of a sample of known X-ray emitting Gigahertz-peaked-spectrum galaxies with
compact-symmetric-object morphology (GPS/CSOs) that lacked an HI absorption
detection. We combined radio and X-ray data of the full sample of X-ray
emitting GPS/CSOs and found a significant, positive correlation between the
column densities of the total and neutral hydrogen ($N_{\rm H}$ and $N_{\rm
HI}$, respectively). Using a Bayesian approach, we simultaneously quantified
the parameters of the $N_{\rm H} - N_{\rm HI}$ relation and the intrinsic
spread of the data set. For a specific subset of our sample, we found $N_{\rm
H} \propto N_{\rm HI}^b$, with $b=0.93^{+0.49}_{-0.33}$, and $\sigma_{int}
(N_{\rm H})= 1.27^{+1.30}_{-0.40}$. The $N_{\rm H} - N_{\rm HI}$ correlation
suggests a connection between the physical properties of the radio and X-ray
absorbing gas.Comment: 6 pages, 3 figures, in press for Astronomische Nachrichten.
  Contribution to the Proceedings of the "Fifth Workshop on Compact Steep
  Spectrum and GHz-Peaked Spectrum Radio Sources", held in Rimini (Italy) in
  May 201
PKS B1718-649: an HI and H2 perspective on the birth of a compact radio
  source

We present neutral hydrogen (HI) and warm molecular hydrogen (H2)
observations of the young (10^2 years) radio galaxy PKS B1718-649. We study the
morphology and the kinematics of both gas components, focusing, in particular,
on their properties in relation to the triggering of the radio activity. The
regular kinematics of the large scale HI disk, seen in emission, suggests that
an interaction event occurred too long ago to be responsible for the recent
triggering of the radio activity. In absorption, we detect two absorption lines
along the narrow line of sight of the compact (r<2 pc) radio source. The lines
trace two clouds with opposite radial motions. These may represent a population
of clouds in the very inner regions of the galaxy, which may be involved in
triggering the radio activity. The warm molecular hydrogen (H2 1-0 S(1)
ro-vibrational line) in the innermost kilo-parsec of the galaxy appears to be
distributed in a circum-nuclear disk following the regular kinematics of the HI
and of the stellar component. An exception to this behaviour arises only in the
very centre, where a highly dispersed component is detected. These particular
HI and H2 features suggest that a strong interplay between the radio source and
the surrounding ISM is on-going. The physical properties of the cold gas in the
proximity of the radio source may regulate the accretion recently triggered in
this AGN.Comment: 5 pages, 4 figures; conference proceeding "5TH WORKSHOP ON COMPACT
  STEEP SPECTRUM AND GHZ-PEAKED SPECTRUM RADIO SOURCES
Tracing the neutral gas environments of young radio AGN with ASKAP

At present neutral atomic hydrogen (HI) gas in galaxies at redshifts above $z
\sim 0.3$ (the extent of 21-cm emission surveys in individual galaxies) and
below $z \sim 1.7$ (where the Lyman-$\alpha$ line is not observable with
ground-based telescopes) has remained largely unexplored. The advent of
precursor telescopes to the Square Kilometre Array will allow us to conduct the
first systematic radio-selected 21-cm absorption surveys for HI over these
redshifts. While HI absorption is a tracer of the reservoir of cold neutral gas
in galaxies available for star formation, it can also be used to reveal the
extreme kinematics associated with jet-driven neutral outflows in radio-loud
active galactic nuclei. Using the six-antenna Boolardy Engineering Test Array
of the Australian Square Kilometre Array Pathfinder, we have demonstrated that
in a single frequency tuning we can detect HI absorption over a broad range of
redshifts between $z = 0.4$ and $1.0$. As part of our early science and
commissioning program, we are now carrying out a search for absorption towards
a sample of the brightest GPS and CSS sources in the southern sky. These
intrinsically compact sources present us with an opportunity to study the
circumunuclear region of recently re-started radio galaxies, in some cases
showing direct evidence of mechanical feedback through jet-driven outflows.
With the sensitivity of the full ASKAP array we will be able to study the
kinematics of atomic gas in a few thousand radio galaxies, testing models of
radio jet feedback well beyond the nearby UniverseComment: 5 pages, 3 figures. Accepted for publication in Astronomische
  Nachrichten. In proceedings of the "5th Workshop on CSS and GPS radio
  sources", held in Rimini (Italy) in May 201
Fast outflows in broad absorption line quasars and their connection with
  CSS/GPS sources

Broad absorption line quasars are among the objects presenting the fastest
outflows. The launching mechanism itself is not completely understood. Models
in which they could be launched from the accretion disk, and then curved and
accelerated by the effect of the radiation pressure, have been presented. We
conducted an extensive observational campaign, from radio to optical band, to
collect information about their nature and test the models present in the
literature, the main dichotomy being between a young scenario and an
orientation one. We found a variety of possible orientations, morphologies, and
radio ages, not converging to a particular explanation for the BAL phenomenon.
From our latest observations in the m- and mm-band, we obtained an indication
of a lower dust abundance with respect to normal quasars, thus suggesting a
possible feedback process on the host galaxy. Also, in the low-frequency regime
we confirmed the presence of CSS components, sometime in conjunction with a GPS
one already detected at higher frequencies. Following this, about 70% of our
sample turns out to be in a GPS or CSS+GPS phase. We conclude that fast
outflows, responsible for the BAL features, can be more easily present among
objects going through a restarting or just-started radio phase, where radiation
pressure can substantially contribute to their acceleration.Comment: accepted for publication on A
Sunspot numbers based on historic records in the 1610s - early
  telescopic observations by Simon Marius and others

Hoyt & Schatten (1998) claim that Simon Marius would have observed the sun
from 1617 Jun 7 to 1618 Dec 31 (Gregorian calendar) all days, except three
short gaps in 1618, but would never have detected a sunspot -- based on a
quotation from Marius in Wolf (1857), but misinterpreted by Hoyt & Schatten.
Marius himself specified in early 1619 that "for one and a half year ... rather
few or more often no spots could be detected ... which was never observed
before" (Marius 1619). The generic statement by Marius can be interpreted such
that the active day fraction was below 0.5 (but not zero) from fall 1617 to
spring 1619 and that it was 1 before fall 1617 (since August 1611). Hoyt &
Schatten cite Zinner (1952), who referred to Zinner (1942), where observing
dates by Marius since 1611 are given, but which were not used by Hoyt &
Schatten. We present all relevant texts from Marius where he clearly stated
that he observed many spots in different form on and since 1611 Aug 3 (Julian)
= Aug 13 (Greg.) (on the first day together with Ahasverus Schmidnerus), 14
spots on 1612 May 30 (Julian) = Jun 9 (Greg.), which is consistent with
drawings by Galilei and Jungius for that day, the latter is shown here for the
first time, at least one spot on 1611 Oct 3 and/or 11 (Julian), i.e. Oct 13
and/or 21 (Greg.), when he changed his sunspot observing technique, he also
mentioned that he has drawn sunspots for 1611 Nov 17 (Julian) = Nov 27 (Greg.),
in addition to those clearly datable detections, there is evidence in the texts
for regular observations. ... Sunspots records by Malapert from 1618 to 1621
show that the last low-latitude spot was seen in Dec 1620, while the first
high-latitude spots were noticed in June and Oct 1620, so that the Schwabe
cycle turnover (minimum) took place around that time, ...Comment: 40 pages with 6 tables and 13 figures (paper in press), Astronomical
  Notes 201
Is the semi-regular variable RU Vulpeculae undergoing a helium-shell
  flash?

The semi-regular variable star RU Vulpeculae (RU Vul) is being observed
visually since 1935. Its pulsation period and amplitude are declining since
$\sim1954$. A leading hypothesis to explain the period decrease in asymptotic
giant branch (AGB) stars such as RU Vul is an ongoing flash of the He-burning
shell, also called a thermal pulse (TP), inside the star. In this paper, we
present a CCD photometric light curve of RU Vul, derive its fundamental
parameters, and test if the TP hypothesis can describe the observed period
decline. We use CCD photometry to determine the present-day pulsation period
and amplitude in three photometric bands, and high-resolution optical
spectroscopy to derive the fundamental parameters. The period evolution of RU
Vul is compared to predictions by evolutionary models of the AGB phase. We find
that RU Vul is a metal-poor star with a metallicity $[{\rm M}/{\rm
H}]=-1.59\pm0.05$ and an effective surface temperature of $T_{\rm
eff}=3634\pm20$ K. The low metallicity of RU Vul and its kinematics indicate
that it is an old, low-mass member of the thick disc or the halo population.
The present day pulsation period determined from our photometry is $\sim108$ d,
the semi-amplitude in the V-band is $0.39\pm0.03$ mag. The observed period
decline is found to be well matched by an evolutionary AGB model with stellar
parameters comparable to those of RU Vul. We conclude that the TP hypothesis is
in good agreement with the observed period evolution of RU Vul.Comment: 7 pages, 6 figures, 1 table, accepted for publication by A
Application of the relativistic precession model to the accreting
  millisecond X-ray pulsar IGR J17511-3057

The observation of a pair of simultaneous twin kHz QPOs in the power density
spectrum of a neutron star or a black hole allows its mass-angular-momentum
relation to be constrained. Situations in which the observed simultaneous pairs
are more than one allow the different models of the kHz QPOs to be falsified.
Discrepancy between the estimates coming from the different pairs would call
the used model into question. In the current paper the relativistic precession
model is applied to the twin kHz QPOs that appear in the light curves of three
groups of observations of the accreting millisecond X-ray pulsar IGR
J17511-3057. It was found that the predictions of one of the groups are
practically in conflict with the other two. Another interesting result is that
the region in which the kHz QPOs have been born is rather broad and extends
quite far from the ISCO.Comment: accepted for publication in Astronomische Nachrichte
Primordial magnetic fields in the $f^{2}FF$ model in large field
  inflation under de Sitter and power law expansion

We use the $f^{2}FF$ model to study the generation of primordial magnetic
fields (PMF) in the context of large field inflation (LFI), described by the
potential, $V \sim M \phi^{p}$. We compute the magnetic and electric spectra
for all possible values of the model parameters under de Sitter and power law
expansion. We show that scale invariant PMF are not obtained in LFI to first
order in the slow roll approximation, if we impose the constraint
$V(\phi=0)\sim 0$. Alternatively, if these constraints are relaxed, the scale
invariant PMF can be generated. The associated electric field energy can fall
below the energy density of inflation, $\rho_{\rm{Inf}}$ for the ranges of
comoving wavenumbers, $ k > 8 \times 10^{-7} \rm{Mpc^{-1}}$ and $ k > 4 \times
10^{-6} \rm{Mpc^{-1}}$ in de Sitter and power law (PL) expansion. Further, it
can drop below $\rho_{\rm{Inf}}$ on the ranges, e-foldings $N > 51$, $p<1.66$,
$p >2.03$, $l_0 > 3 \times 10^5 {M_{\rm{Pl}}}^{-1} (H_i < 3.3 \times 10^{-6}
M_{\rm{Pl}})$, and $M > 2.8 \times 10^{-3} M_{\rm{Pl}}$. All of the above
ranges fit with the observational constraints.Comment: 17 pages, 12 figures, Astronomische Nachrichten (AN) Vol.337, Issue
  No.3, 201
Mattig's relation and dynamical distance indicators

We discuss how the redshift (Mattig) method in Friedmann cosmology relates to
dynamical distance indicators based on Newton's gravity (Teerikorpi 2011). It
belongs to the class of indicators where the relevant length inside the system
is the distance itself (in this case the proper metric distance). As the
Friedmann model has Newtonian analogy, its use to infer distances has
instructive similarities to classical dynamical distance indicators. In view of
the theoretical exact linear distance-velocity law, we emphasize that it is
conceptually correct to derive the cosmological distance via the route:
redshift (primarily observed) --> space expansion velocity (not directly
observed) --> metric distance (physical length in "cm"). Important properties
of the proper metric distance are summarized.Comment: 3 pages, 0 figure
Search for transiting exoplanets and variable stars in the open cluster
  NGC 7243

We report results of the first five observing campaigns for the open stellar
cluster NGC 7243 in the frame of project Young Exoplanet Transit Initiative
(YETI). The project focuses on the monitoring of young and nearby stellar
clusters, with the aim to detect young transiting exoplanets, and to study
other variability phenomena on time-scales from minutes to years. After five
observing campaigns and additional observations during 2013 and 2014, a clear
and repeating transit-like signal was detected in the light curve of
J221550.6+495611. Furthermore, we detected and analysed 37 new eclipsing binary
stars in the studied region. The best fit parameters and light curves of all
systems are given. Finally, we detected and analysed 26 new, presumably
pulsating variable stars in the studied region. The follow-up investigation of
these objects, including spectroscopic measurements of the exoplanet candidate,
is currently planned.Comment: 25 pages, AN accepte
All-spherical telescope with extremely wide field of view

An all-spherical catadioptic telescope with the angular field of view of
several tens of degrees in diameter and spherical focal surface is proposed for
the monitoring of large sky areas. We provide a few examples of such a system
with the apertures up to 800 mm and the field of view $30^\circ$ and $40^\circ$
in diameter. The curvature of the focal surface is repaid by high performance
of the telescope. In particular, the diameter of a circle, that includes 80% of
energy in the polychromatic image of a star, is in the range $1.4'' - 1.9''$
across the field of $30^\circ$ size and $2.2'' - 2.9''$ for the field of
$40^\circ$ size. Some ways of working with curved focal surfaces are discussed.Comment: Version 2. Accepted by Astron. Nachr. / A
Chemical spots on the surface of the strongly magnetic Herbig Ae star HD
  101412

Due to the knowledge of the rotation period and the presence of a rather
strong surface magnetic field, the sharp-lined young Herbig Ae star HD 101412
with a rotation period of 42 d has become one of the most well-studied targets
among the Herbig Ae stars. High-resolution HARPS polarimetric spectra of HD
101412 were recently obtained on seven different epochs. Our study of the
spectral variability over the part of the rotation cycle covered by HARPS
observations reveals that the line profiles of the elements Mg, Si, Ca, Ti, Cr,
Mn, Fe, and Sr are clearly variable while He exhibits variability that is
opposite to the behaviour of the other elements studied. Since classical Ap
stars usually show a relationship between the magnetic field geometry and the
distribution of element spots, we used in our magnetic field measurements
different line samples belonging to the three elements with the most numerous
spectral lines, Ti, Cr, and Fe. Over the time interval covered by the available
spectra, the longitudinal magnetic field changes sign from negative to positive
polarity. The distribution of field values obtained using Ti, Cr, and Fe lines
is, however, completely different compared to the magnetic field values
determined in previous low-resolution FORS 2 measurements, where hydrogen
Balmer lines are the main contributors to the magnetic field measurements,
indicating the presence of concentration of the studied iron-peak elements in
the region of the magnetic equator. Further, we discuss the potential role of
contamination by the surrounding warm circumstellar matter in the appearance of
Zeeman features obtained using Ti lines