pinecone/core-2020-05-10-deduplication huggingface dataset:
Data mining of near Earth asteroids in the Subaru Suprime-Cam archive

As part of the EURONEAR project, almost 70,000 mosaic Suprime-Cam images
taken between 1999 and 2013 were data mined for about 9,800 near Earth
asteroids (NEAs) known by 2013 May. Using our PRECOVERY server and the "Find
Subaru CCD" tool, we scrutinized 4,186 candidate CCD images possibly holding
518 NEAs. We found 113 NEAs as faint as V<25 magnitude, their positions being
measured in 589 images using Astrometrica, then reported to the Minor Planet
Center. Among them, 18 objects represent encounters of previously single
opposition NEAs, their orbital arcs being extended by up to 10 years. In the
second part of this work we searched for unknown NEAs in 78 sequences (780 CCD
fields) of 4-5 mosaic images selected from the same Suprime-Cam archive and
totaling 16.6 sq.deg, with the aim to assess the faint NEA distribution
observable with an 8-m class survey. A total of 2,018 moving objects were
measured, from which we identified 18 better NEA candidates. Using the R_c
filter in good weather conditions, mostly dark time and sky directions slightly
biased towards the ecliptic, at least one NEA could be discovered in every 1
sq.deg surveyed.Comment: Accepted for publication in Astronomical Nachrichten (7 Jan 2017
On the possibility of helicity oscillations in the saturation of the
  Tayler instability

Recent numerical results of current-driven instabilities at low magnetic
Prandtl number and high Hartmann number support the possibility of a saturation
state characterized by helicity oscillations. We investigate the underlying
mechanism by analyzing this possibility using an higher-order Landau-Ginzburg
effective Lagrangian for the weakly non-linear amplitude dynamics, where the
magnetic and velocity perturbations are linearly dependent. We find that, if
the mirror symmetry between left- and right-handed modes is spontaneously
broken, it is impossible to achieve an oscillating helical state. We argue that
the result is likely to hold also adding higher-order terms and in the presence
of an explicit symmetry breaking. We conclude that an oscillating saturating
state for the Tayler instability is unlikely to depend on the interaction of
chiral modes.Comment: 10 pages, 6 figure
On the relationship between the continuum of interstellar extinction
  curves, the 2200 \AA\ bump, and the diffuse interstellar bands

A previous article argued that the antagonism between sight-lines with and
without a bump at 2200 \AA\ disappears, and that the observed properties of
interstellar extinction can be globally understood, if it is accepted that
scattered starlight contaminates the observed spectrum of reddened stars. The
present paper develops this new paradigm by providing a better understanding of
the characteristics of this scattered light. It further examines the
consequences of this revision of interstellar extinction theory for
interpreting the 2200 \AA\ bump and the diffuse interstellar bands (DIBs). Two
implications are worth noting: (1) the effect of interstellar extinction on
cosmic distance estimations needs to be reconsidered; (2) it is unnecessary to
invoke hypothetical particles, such as Poly Aromatic Hydrogenated molecules
(PAHs), to explain the peculiarities of interstellar extinction. Hydrogen, by
far the most abundant constituent of interstellar clouds, should alone account
for the three major features of interstellar extinction: the departure of the
continuum from linearity, the bump, and the DIBs.Comment: Second version with a redrafted and revised text. 23 pages, 2 figure
Surface magnetism of cool stars

Magnetic fields are essential ingredients of many physical processes in the
interiors and envelopes of cool stars. Yet their direct detection and
characterisation is notoriously difficult, requiring high-quality observations
and advanced analysis techniques. Significant progress has been recently
achieved by several types of direct magnetic field studies on the surfaces of
cool active stars. In particular, complementary techniques of the field
topology mapping with polarisation data and total magnetic flux measurements
from intensity spectra have been systematically applied to different classes of
active stars leading to interesting and occasionally controversial results. In
this paper we summarise the current status of direct magnetic field studies of
cool stars, and investigations of surface inhomogeneities caused by the field,
based on the material presented at the Cool Stars 19 splinter session.Comment: Summary of the splinter session "Surface Magnetism of Cool Stars" at
  the Cool Stars 19 conference; to be published in Astronomische Nachrichte
A TGAS/Gaia DR1 parallactic distance to the sigma Orionis cluster

With the new Tycho-Gaia Astrometric Solution, I derive a new parallactic
distance to the young sigma Orionis open cluster, which is a cornerstone region
for studying the formation and evolution of stars and substellar objects from
tens of solar masses to a few Jupiter masses. I started with the list of the 46
brightest cluster stars of Caballero (2007). After identifying the 24 TGAS
stars in the 30 arcmin-radius survey area and accounting for 11 FGKM-type
dwarfs and giants in the fore- and background, I got a list of 13 cluster
members and candidates with new parallaxes. Of them, I discarded five cluster
member candidates with questionable features of youth and/or discordant
parallaxes and proper motions, including a distant Herbig Ae/Be star, and
proceeded with the remaining eight stars. The sigma Orionis mean heliocentric
distance is d =360^{+44}_{-35} pc, which is consistent with a contemporaneous
interferometric determination that concludes a two-decade dispute on the
cluster distance. As a by-product, the re-classification of those five cluster
member candidates, now interlopers, shows a manifest deficit of cluster stars
between 1.2 and 2.1 Msol, which leaves the door open to new astrometric
membership analyses with the next Gaia data releases.Comment: Astronomische Nachrichten, accepte
Wide sigma Orionis binaries resolved by UKIDSS

In spite of its importance for the study of star formation at all mass
domains, the nearby young sigma Orionis cluster still lacks a comprehensive
survey for multiplicity. We try to fill that observational gap by looking for
wide resolved binaries with angular separations between 0.4 and 4.0 arcsec. We
search for companions to 331 catalogued cluster stellar members and candidates
in public K-band UKIDSS images outside the innermost 1 arcmin, which is
affected by the glare of the bright, eponymous sigma Ori multiple system, and
investigate their cluster membership with colour-magnitude diagrams and
previous knowledge of youth features. Of the 18 identified pairs, ten have very
low individual probabilities of chance alignment (< 1 %) and are considered
here as physical pairs. Four of them are new, while the other six had been
discovered previously, but never investigated homogeneously and in detail.
Projected physical separations and magnitude differences of the ten probably
bound pairs range from 180 to 1220 au, and from 0.0 to 3.4 mag in K,
respectively. Besides, we identify two cluster stars with elongated point
spread functions. We determine the minimum frequency of wide multiplicity in
the interval of projected physical separations s = 160-1600 au in sigma Orionis
at 3.0^{+1.2}_{-1.1} %. We discover a new Lindroos system, find that massive
and X-ray stars tend to be in pairs or trios, conclude that multiplicity
truncates circumstellar discs and enhances X-ray emission, and ascribe a
reported lithium depletion in a young star to unresolved binarity in spectra of
moderate resolution. When accounting for all know multiples, including
spectroscopic binaries, the minimum frequency of multiplicity increases to
about 10 %, which implies that of the order of 80-100 unknown multiple systems
still await discovery in sigma Orionis.Comment: Astronomische Nachrichten, accepte
Sun-like stars unlike the Sun: Clues for chemical anomalies of cool
  stars

We present a summary of the splinter session "Sun-like stars unlike the Sun"
that was held on 09 June 2016 as part of the Cool Stars 19 conference (Uppsala,
Sweden). We discussed the main limitations (in the theory and observations) in
the derivation of very precise stellar parameters and chemical abundances of
Sun-like stars. We outlined and discussed the most important and most debated
processes that can produce chemical peculiarities in solar-type stars. Finally,
in an open discussion between all the participants we tried to identify new
pathways and prospects towards future solutions of the currently open
questions.Comment: Resubmitted to AN after minor revisio
High-resolution X-ray spectroscopy: the coming-of-age

Since the launch of Chandra and XMM-Newton, high-resolution X-ray spectra of
cosmic sources of all kinds have become available. These spectra have resulted
in major scientific breakthroughs. However, due to the techniques used, in
general high-quality spectra can only be obtained for the brightest few sources
of each class. Moreover, except for the most compact extended sources, like
cool core clusters, grating spectra are limited to point sources. Hitomi made
another major step forward, in yielding for the first time a high-quality
spectrum of an extended source, and improved spectral sensitivity in the Fe-K
band. For point sources with the proposed Arcus mission, and for all sources
with the launch of Athena, X-ray spectroscopy will become mature. It allows us
to extend the investigations from the few handful of brightest sources of each
category to a large number of sources far away in space and time, or to get
high time-resolution, high-spectral resolution spectra of bright time variable
sources.Comment: 7 pages, 9 figures, to appear in Astronomische Nachrichten, presented
  at the XMM-Newton: The Next Decade conference, ESAC, Madrid, Spain, 9 - 11
  May 201
Cosmic X-ray surveys of Active Galactic Nuclei: synergy between X-ray
  and infrared observations

We briefly review the synergy between X-ray and infrared observations for
Active Galactic Nuclei (AGNs) detected in cosmic X-ray surveys, primarily with
XMM-Newton, Chandra, and NuSTAR. We focus on two complementary aspects of this
X-ray-infrared synergy (1) the identification of the most heavily obscured AGNs
and (2) the connection between star formation and AGN activity. We also briefly
discuss future prospects for X-ray-infrared studies over the next decade.Comment: 6 pages, 5 figures, accepted for publication in Astronomische
  Nachrichten as part of the proceedings of the workshop "XMM-Newton: The Next
  Decade
Perspectives for observing hot massive stars with XMM-Newton in the
  years 2017 -- 2027

XMM-Newton has deeply changed our picture of X-ray emission of hot, massive
stars. High-resolution X-ray spectroscopy as well as monitoring of these
objects helped us gain a deeper insight into the physics of single massive
stars with or without magnetic fields, as well as of massive binary systems,
where the stellar winds of both stars interact. These observations also
revealed a number of previously unexpected features that challenge our
understanding of the dynamics of the stellar winds of massive stars. I briefly
summarize the results obtained over the past 15 years and highlight the
perspectives for the next decade. It is anticipated that coordinated (X-ray and
optical or UV) monitoring and time-critical observations of either single or
binary massive stars will become the most important topics in this field over
the coming years. Synergies with existing or forthcoming X-ray observatories
(NuSTAR, Swift, eROSITA) will also play a major role and will further enhance
the importance of XMM-Newton in our quest for understanding the physics of hot,
massive stars.Comment: To appear in a special issue of Astronomical Notes. Proceedings of
  the workshop "XMM-Newton: The Next Decade", (ESAC, Villafranca del Castillo,
  Spain, 9-11 May 2016
Follow-up of isolated neutron star candidates from the eROSITA survey

Peculiar groups of X-ray emitting isolated neutron stars, which include
magnetars, the "Magnificent Seven", and central compact objects in supernova
remnants, escape detection in standard pulsar surveys. Yet, they constitute a
key element in understanding the neutron star evolution and phenomenology.
Their use in population studies in the galactic scale has been hindered by the
scarcity of their detection. The all-sky survey of eROSITA on-board the
forthcoming Spectrum-RG mission has the unique potential to unveil the X-ray
faint part of the population and constrain evolutionary models. To create a
forecast for the four-year all-sky survey, we perform Monte Carlo simulations
of a population synthesis model, where we follow the evolutionary tracks of
thermally emitting neutron stars in the Milky Way and test their detectability.
In this work, we discuss strategies for pinpointing the most promising
candidates for follow-up observing campaigns using current and future
facilities.Comment: 6 pages, 6 figures; to appear in the proceedings of the "XMM-Newton:
  The Next Decade" Science Workshop; Astronomical Notes, in pres
A multi-observatory database of X-ray pulsars in the Magellanic Clouds

Using hundreds of XMM-Newton and Chandra archival observations and nearly a
thousand RXTE observations, we have generated a comprehensive library of the
known pulsars in the Small and Large Magellanic Clouds (SMC, LMC). The pulsars
are detected multiple times across the full parameter spaces of X-ray
luminosity ($L_X= 10^{31-38}$~erg/s) and spin period ( P$<$1s -- P$>$1000s) and
the library enables time-domain studies at a range of energy scales. The high
time-resolution and sensitivity of the EPIC cameras are complemented by the
angular resolution of Chandra and the regular monitoring of RXTE. Our
processing %$\sim$15 year pipeline uses the latest calibration files and
software to generate a suite of useful products for each pulsar detection:
event lists, high time-resolution light curves, periodograms, spectra, and
complete histories of $\dot{P}$, the pulsed fraction, etc., in the broad
(0.2-12 keV), soft (0.2-2 keV), and hard (2-12 keV) energy bands. After
combining the observations from these telescopes, we found that 28 pulsars show
long-term spin up and 25 long-term spin down. We also used the faintest and
brightest sources to map out the lower and upper boundaries of
accretion-powered X-ray emission: the propeller line and the Eddington line,
respectively. We are in the process of comparing the observed pulse profiles to
geometric models of X-ray emission in order to constrain the physical
parameters of the pulsars. Finally we are preparing a public release of the
library so that it can be used by others in the astronomical community.Comment: 6 pages, 6 figure
Leveraging High Resolution Spectra to Understand Black Hole Spectra

For the past 17 years, both XMM-Newton and Chandra have brought the powerful
combination of high spatial and spectral resolution to the study of black hole
systems. Each of these attributes requires special consideration--- in
comparison to lower spatial resolution, CCD quality spectra--- when modeling
observations obtained by these spacecraft. A good understanding of the high
resolution spectra is in fact required to model properly lower resolution CCD
spectra, with the Reflection Grating Spectrometer (RGS) instrument on
XMM-Newton maintaining the highest "figure of merit" at soft X-ray energies for
all missions flying or currently planned for the next decade. Thanks to its
even higher spectral resolution, the use of Chandra-High Energy Transmission
Gratings (HETG), albeit with longer integration times, allows for one to bring
further clarity to RGS studies. A further promising route for continued studies
is the combination of high spectral resolution at soft X-rays, via RGS and/or
HETG, with contemporaneous broadband coverage extending to hard X-rays (e.g.,
NuSTAR or INTEGRAL spectra). Such studies offer special promise for answering
fundamental questions about accretion in black hole systems; however, they have
received only moderate consideration to date. This may be due in part to the
difficulty of analyzing high resolution spectra. In response, we must continue
to develop software tools that make the analysis of high resolution X-ray
spectra more accessible to the wider astrophysics community.Comment: 7 pages, 5 figures, to appear in Astronomische Nachrichten, presented
  at the XMM-Newton: The Next Decade conference, ESAC, Madrid, Spain, 9 - 11
  May 201
Ultrafast outflows in ultraluminous X-ray sources

Ultraluminous X-ray sources (ULXs) are bright extragalactic sources with
X-ray luminosities above 10^39 erg/s powered by accretion onto compact objects.
According to the first studies performed with XMM-Newton ULXs seemed to be
excellent candidates to host intermediate-mass black holes (10^2-4 solar
masses). However, in the last years the interpretation of super-Eddington
accretion onto stellar-mass black holes or neutron stars for most ULXs has
gained a strong consensus. One critical missing piece to confirm the
super-Eddington scenario was the direct detection of the massive,
radiatively-driven winds expected as atomic emission/absorption lines in ULX
spectra. The first evidence for winds was found as residuals in the soft X-ray
spectra of ULXs. Most recently we have been able to resolve these residuals
into rest-frame emission and blueshifted (~0.2c) absorption lines arising from
highly ionized gas in the deep high-resolution XMM-Newton spectra of two
ultraluminous X-ray sources. The compact object is therefore surrounded by
powerful ultrafast winds as predicted by models of hyper-Eddington accretion.
Here we discuss the relevance of these discoveries and the importance of
further, deep, XMM-Newton observations of powerful winds in many other
ultraluminous X-ray sources to estimate the energetics of the wind, the
geometry of the system, and the masses of the central accretors.Comment: 6 pages, 5 figures, to appear in proceedings of the conference
  "XMM-Newton: The Next Decade
High-Redshift AGNs and the Next Decade of Chandra and XMM-Newton

We briefly review how X-ray observations of high-redshift active galactic
nuclei (AGNs) at z = 4-7 have played a critical role in understanding their
basic demographics as well as their physical processes; e.g., absorption by
nuclear material and winds, accretion rates, and jet emission. We point out
some key remaining areas of uncertainty, highlighting where further Chandra and
XMM-Newton observations/analyses, combined with new multiwavelength survey
data, can advance understanding over the next decade.Comment: Proceedings paper for "XMM-Newton: The Next Decade" (held in 2016
  May); Astronomische Nachrichten, in press (second version has small
  improvements, e.g., in response to referee feedback
Exploring accretion disc physics and black hole growth with regular
  monitoring of ultrafast AGN winds

15 years of XMM-Newton observations have established that ultra-fast, highly
ionized winds are common in radio-quiet AGN. A simple theory of
Eddington-limited accretion correctly predicts the typical velocity (~0.1c) and
high ionization of such winds, with observed flow energy capable of ejecting
star-forming gas. With a recent extended XMM-Newton observation of the
archetypal UFO, PG1211+143, revealing a more complex flow pattern, we suggest
that targetted observations over the next decade offer unique potential for
probing the inner accretion disc structure and SMBH growth.Comment: Proceedings of conference 'XMM-the next decade', at ESAC 10-13 May
  2016. To be published in Astron Nachr, 2017. This replacement corrects a
  misplaced sentence in the original versio
Tidal Disruption of Stars by Supermassive Black Holes -- XMM-Newton
  Highlights and the Next Decade

This article provides a summary of XMM-Newton highlights on stellar tidal
disruption events. First found with ROSAT, ongoing and upcoming sky surveys
will detect these events in the 1000s. In X- rays, tidal disruption events
(TDEs) provide us with powerful new probes of accretion physics under extreme
conditions and on short timescales and of relativistic effects near the SMBH,
of the formation and evolution of disk winds near or above the Eddington limit,
and of the processes of high-energy emission from newly launched radio jets.
TDEs serve as signposts of the presence of dormant, single black holes at the
cores of galaxies, and of binary black holes as well, since TDE lightcurves are
characteristically different in the latter case. XMM-Newton has started to
contribute to all of these topics, and a rich discovery space is opening up in
the next decade.Comment: Review, given at "XMM-Newton - The next decade" (Madrid, May 2016).
  Submitted August 2016. In press with Astronomische Nachrichte
Unveiling multiple AGN activity in galaxy mergers

In this paper we present an overview of the MAGNA (Multiple AGN Activity)
project aiming at a comprehensive study of multiple supemassive black hole
systems. With the main goal to characterize the sources in merging systems at
different stages of evolution, we selected a sample of objects optically
classified as multiple systems on the basis of emission line diagnostics and
started a massive multiband observational campaign. Here we report on the
discovery of the exceptionally high AGN density compact group SDSS~J0959+1259.
A multiband study suggests that strong interactions are taking place among its
galaxies through tidal forces, therefore this system represents a case study
for physical mechanisms that trigger nuclear activity and star formation. We
also present a preliminary analysis of the multiple AGN system
SDSS~J1038+3921.}Comment: Proceedings paper for "XMM-Newton: The Next Decade" (held in 2016
  May); accepted to be published in Astronomische Nachrichten / Astronomical
  Notes (AN
The Future of X-ray Reverberation from AGN

XMM-Newton is capable of making a transformational advance in our
understanding of how luminous accreting black holes work, by dedicating about
10 per cent of future observing time to long observations, of order
Megaseconds, to X-ray variable Active Galactic Nuclei (AGN) research. This
would enable reverberation studies, already a commonplace feature of AGN, to
proceed to the next level and follow the behaviour of the powerful dynamic
corona. Such a dedicated legacy programme can only be carried out with
XMM-Newton.Comment: 5 pages, 5 figures for publication in Astronomische Nachrichten as
  part of the proceedings of the workshop "XMM-Newton: The Next Decade
The XMM Cluster Outskirts Project (X-COP)

Galaxy clusters are thought to grow hierarchically through the continuous
merging and accretion of smaller structures across cosmic time. In the local
Universe, these phenomena are still active in the outer regions of massive
clusters ($R>R_{500}$), where the matter distribution is expected to become
clumpy and asymmetric because of the presence of accreting structures. We
present the XMM-Newton Cluster Outskirts Project (X-COP), which targets the
outer regions of a sample of 13 massive clusters
($M_{500}>3\times10^{14}M_\odot$) in the redshift range 0.04-0.1 at uniform
depth. The sample was selected based on the signal-to-noise ratio in the Planck
Sunyaev-Zeldovich (SZ) survey with the aim of combining high-quality X-ray and
SZ constraints throughout the entire cluster volume. Our observing strategy
allows us to reach a sensitivity of $3\times10^{-16}$ ergs cm$^{-2}$ s$^{-1}$
arcmin$^{-2}$ in the [0.5-2.0] keV range thanks to a good control of systematic
uncertainties. The combination of depth and field of view achieved in X-COP
will allow us to pursue the following main goals: i) measure the distribution
of entropy and thermal energy to an unprecedented level of precision; ii)
assess the presence of non-thermal pressure support in cluster outskirts; iii)
study the occurrence and mass distribution of infalling gas clumps. We
illustrate the capabilities of the program with a pilot study on the cluster
Abell 2142.Comment: 6 pages, 5 figures, accepted for publication in Astronomische
  Nachrichten as part of the proceedings of the workshop "XMM-Newton: The Next
  Decade" (May 9-11, 2016