The need for accurate photometric redshifts estimation is a topic that has fundamental importance in Astronomy, due to the necessity of efficiently obtaining redshift information without the need of spectroscopic analysis. We propose a method for determining accurate multi-modal photo-z probability density functions (PDFs) using Mixture Density Networks (MDN) and Deep Convolutional Networks (DCN). A comparison with a Random Forest (RF) is performed.

In this work, we analysed the physical parameters of the spotless actives regions observed during solar minimum 23 – 24 (2007 – 2010). The study was based on radio maps at 17 GHz obtained by the Nobeyama Radioheliograph (NoRH) and magnetograms provided by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO). The results shows that the spotless active regions presents the same radio characteristics of a ordinary one, they can live in the solar surface for long periods (>10 days), and also can present small flares.

The HASH (Hong Kong/ AAO/ Strasbourg/ Hα) planetary nebula research platform is a unique data repository with a graphical interface and SQL capability that offers the community powerful, new ways to undertake Galactic PN studies. HASH currently contains multi-wavelength images, spectra, positions, sizes, morphologies and other data whenever available for 2401 true, 447 likely, and 692 possible Galactic PNe, for a total of 3540 objects. An additional 620 Galactic post-AGB stars, pre-PNe, and PPN candidates are included. All objects were classified and evaluated following the precepts and procedures established and developed by our group over the last 15 years. The complete database contains over 6,700 Galactic objects including the many mimics and related phenomena previously mistaken or confused with PNe. Curation and updating currently occurs on a weekly basis to keep the repository as up to date as possible until the official release of HASH v1 planned in the near future.

In this contribution we report the current stage of the MOLecular Dissociation (MOL-D) database which is a web service within the Serbian virtual observatory (SerVO) and node within Virtual Atomic and Molecular Data Center (VAMDC). MOL-D is an atomic and molecular (A&M) database devoted to the modelling of stellar atmospheres, laboratory plasmas, industrial plasmas etc. The initial stage of development was done at the end of 2014, when the service for data connected with hydrogen and helium molecular ions was done. In the next stage of the development of MOL-D, we include new cross-sections and rate coefficients for processes which involve species such as XH+, where X is atom of some metal. Data are important for the exploring of the interstellar medium as well as for the early Universe chemistry and for the modeling of stellar and solar atmospheres. In this poster, we present our ongoing work and plans for the future.

As part of a systematic effort to characterize the properties and progenitors of the most luminous planetary nebulae (PNe), we obtained a sample among the brightest PNe in two stellar systems of different metallicities: LMC (Z/Z⊙~0.5) and M31 (Z/Z⊙~1) by means of a combined effort with the VLT and the 10mGTC. Modelling of these data will allow us to infer the masses of the stellar progenitors, gaining insights into the controversial origin of the universal cutoff of the Planetary Nebulae Luminosity Function (PNLF).

In this contribution the focus is on post-AGB binaries. It is now well established that these are often surrounded by stable long-lived circumbinary discs of gas and dust. Here we introduce our monitoring programme with our high-resolution spectrograph HERMES mounted on the 1.2m Mercator telescope. We illustrate the use of time-series high-resolution spectra and show that jets observed in many systems are launched at the location of the companion. The jet is likely originating from a circum-companion accretion disc. The link of these systems to some PNe relies on the detection of similar orbits and hence wide spectroscopic orbits among central stars of PNe. The conclusion is that Keplerian discs as well as circum-companion discs are fundamental to understanding the properties and evolution of these interacting evolved binaries.

We present a statistical study of the dependencies of the shapes and sizes of the photospheric convective cells on the magnetic field properties. This analysis is based on a 2.5 hour long SST observations of active region NOAA 11768. We have blue continuum images taken with a cadence of 5.6 sec that are used for segmentation of individual granules and 270 maps of spectropolarimetric CRISP data allowing us to determine the properties of the magnetic field along with the line-of-sight velocities. The sizes and shapes of the granular cells are dependent on the the magnetic field strength, where the granules tend to be smaller in regions with stronger magnetic field. In the presence of highly inclined magnetic fields, the eccentricity of granules is high and we do not observe symmetric granules in these regions. The mean up-flow velocities in granules as well as the granules intensities decrease with increasing magnetic field strength.

The time domain is the emerging forefront of astronomical research with new facilities and instruments providing unprecedented amounts of data on the temporal behavior of astrophysical populations. Dealing with the size and complexity of this requires new techniques and methodologies. Quasars are an ideal work set for developing and applying these: they vary in a detectable but not easily quantifiable manner whose physical origins are poorly understood. In this paper, we will review how quasars are identified by their variability and how these techniques can be improved, what physical insights into their variability can be gained from studying extreme examples of variability, and what approaches can be taken to increase the number of quasars known. These will demonstrate how astroinformatics is essential to discovering and understanding this important population.

Astronomy is rapidly approaching an impasse: very large datasets require remote or cloud-based parallel processing, yet many astronomers still try to download the data and develop serial code locally. Astronomers understand the need for change, but the hurdles remain high. We are developing a data archive designed from the ground up to simplify and encourage cloud-based parallel processing. While the volume of data we host remains modest by some standards, it is still large enough that download and processing times are measured in days and even weeks. We plan to implement a python based, notebook-like interface that automatically parallelises execution. Our goal is to provide an interface sufficiently familiar and user-friendly that it encourages the astronomer to run their analysis on our system in the cloud—astroinformatics as a service. We describe how our system addresses the approaching impasse in astronomy using the SAMI Galaxy Survey as an example.

Planetary nebulae form in stellar populations with ages from 1 to 10 Gyr, and can be used to trace their star formation histories. Here we apply this to the Galactic bulge, where there are indications both for an old origin and for younger stars. We use new stellar models, which have significant different evolutionary speeds during the post-AGB phase. We apply these new models to a sample of 32 planetary nebulae with HST imaging and VLT spectroscopy. The results show evidence for an old starburst, followed by continuous star formation until at least 2Gyr ago. This agrees very well with recent analysis of colour-magnitude diagrams of the bulge. We show that the new models can also explain the [OIII] luminosity functions, and predict the uniform luminosity cut-off both in spiral galaxies and old elliptical galaxies.

Asymptotic giant branch (AGB) stars are among the most important gas and dust polluters of the Universe. The latest AGB evolutionary models take into account dust production in the circumstellar envelope of these stars, starting from a detailed computation of the main physical processes and chemical surface variations occurring in this evolutionary phase. Following the formation and growth of dust particles, they provide the unique possibility of interpreting the AGB population observed in resolved galaxies. The first application was for the Spitzer observations of dusty AGBs in the Magellanic Clouds, characterising carbon-rich and oxygen-rich stars in terms of initial mass, epoch of star formation, evolutionary time on the AGB and dust contribution. The same set of models are able to interpret the CNO surface abundances observed for the PNe of the same galaxies.

During the PMS, structure and rotation rate of stars evolve significantly. We wish to assess the consequences of these drastic changes on stellar dynamo, internal magnetic field topology and activity level by mean of HPC simulations with the ASH code. To answer this question, we develop 3D MHD simulations that represent specific stages of stellar evolution along the PMS. We choose five different models characterized by the radius of their radiative zone following an evolutionary track, from 1 Myr to 50 Myr, computed by a 1D stellar evolution code. We introduce a seed magnetic field in the youngest model and then we spread it through all simulations. First of all, we study the consequences that the increase of rotation rate and the change of geometry of the convective zone have on the dynamo field that exists in the convective envelop. The magnetic energy increases, the topology of the magnetic field becomes more complex and the axisymmetric magnetic field becomes less predominant as the star ages. The computation of the fully convective MHD model shows that a strong dynamo develops with a ratio of magnetic to kinetic energy reaching equipartition and even super-equipartition states in the faster rotating cases. Magnetic fields resulting from our MHD simulations possess a mixed poloidal-toroidal topology with no obvious dominant component. We also study the relaxation of the vestige dynamo magnetic field within the radiative core and found that it satisfies stability criteria. Hence it does not experience a global reconfiguration and instead slowly relaxes by retaining its mixed poloidal-toroidal topology.

The catalog of 38,000 chromospherically active RAVE dwarfs represents one of the largest samples of young active solar-like and later-type single field stars in the Solar neighbourhood. It was established from the unbiased magnitude limited RAVE Survey using an unsupervised stellar classification algorithm based merely on stellar fluxes (Ca II infrared triplet). Using a newly-calibrated age-activity relation, ~15,000 active stars are estimated to be younger than 1 Gyr. Almost 2000 stars are presumably younger than ~100 Myr and possibly still in the pre-main sequence phase, the latter being supported by their significant offset from the main sequence in the N UV − V versus J − K space. 16,000 stars from the sample have positional and velocity vectors available (using TGAS parallaxes and proper motions and radial velocities from RAVE).

The stellar life cycle is dominated by phases such as the hydrogen-burning stage and the remnant white dwarf cooling phase. However, between these two stages, stars dramatically transform themselves by losing the bulk of their mass. Planetary nebulae (PNe) provide a powerful clue to the processes involved in this transformation, but they are very complex. Over the past 15 years, a new wave of imaging and spectroscopy programs have uncovered the remnants of PNe, white dwarfs, in a wide range of well-measured environments. With this we can map the masses and temperatures of the stellar remnants to the properties of their progenitors. This work has now led to the first uniform mapping of the initial-final mass relation from 1.5 to 7 M⊙. The resulting relation is a fundamental input to our understanding of stellar evolution for low and intermediate-mass stars that produce PNe and has a wide range of applications.

Cosmological simulations allow us to study in detail the evolution of galaxy halos in cluster environments, but the extremely low surface brightness of such components makes it difficult to gather observational constraints. Planetary nebulas (PNs) offer a unique tool to investigate these environments owing to their strong [OIII] emission line. We study the light and kinematics of the Virgo cluster and its central galaxy, M87, prime targets to address the topic of galaxy formation and evolution in dense environments. We make use of a deep and extended PN sample (~300 objects) that extends out to 150 kpc in radius from M87’s centre. We show that at all distance the galaxy halo overlaps with the Virgo intracluster light (ICL). Halo and ICL are dynamically distinct components with different parent stellar populations, consistent with the halo of M87 being redder and more metal rich than the ICL. The synergy between PN kinematic information and deep V/B-band photometry made it possible to unravel an ongoing accretion process in the outskirt of M87. This accretion event represents a non-negligible perturbation of the halo light, showing that this galaxy is still growing by accretion of smaller systems.

A M2.5 solar flare observed by RHESSI in the 6-100 keV range on July 6, 2006 led to a Coronal Mass Ejection (CME). Two compact sources at 12-100 keV are seen at the beginning of the flare, whose further evolution fits well in a loop. Also, time-profiles of the flare at radio wavelengths are compared. The X-ray light-curves at different bands in the 6-100 keV range and radio time profiles show some peaks superimposed on smooth variations. The aim of this work is to compare the X-ray light-curves, of fluxes integrated over the whole source, with the physical parameters of the sources of the flare. Yashiro and Gopalswamy (2009) have found that the fraction of flares that produce CME increases with the flare energy. Here, we look for the characteristics of an M2.5 flare that could make it a generator of a CME. The idea is, in future works, to look in the light-curves of similar flares at other stars for these features. It is found that the CME onset takes place around the time when an X-ray source at 12-25 keV of Chromospheric evaporation stagnates at the loop apex, before the main peak at the light-curve at 25-50 keV and at the radio emission curves. Probably, the amount of evaporated plasma could play some role in triggering the CME.

In this work, we utilize a method based on Wang-Landau Monte Carlo sampling for studying the temperature effects of astrophysically relavant molecules. Anharmonic effects, e.g., resonances, overtones, and combination bands, are fully incoportated in this method. The calculated infrared (IR) spectra are consistent with the experimental data measured by National Institute of Standards and Technology (NIST).

Excess thermal energy within a Charged Coupled Device (CCD) results in excess electrical current that is trapped within the lattice structure of the electronics. This excess signal from the CCD itself can be present through multiple exposures, which will have an adverse effect on its science performance unless it is corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as “dark” images, allow for the measurement of thermal-electron contamination at each pixel of the CCD. This so-called “dark current” can then be subtracted from the science images by re-scaling to the science exposure times. Pixels that have signal above a certain value are traditionally marked as “hot” and flagged in the data quality array. Many users will discard these pixels as being bad. However, these pixels may not be bad in the sense that they cannot be reliably dark-subtracted; if these pixels are shown to be stable over a given anneal period, the charge can be properly subtracted and the extra Poisson noise from this dark current can be taken into account and put into the error arrays.

V4334 Sgr (a.k.a. Sakurai's object) is the central star of an old planetary nebula that underwent a very late thermal pulse a few years before its discovery in 1996. We have been monitoring the evolution of the optical emission line spectrum since 2001. The goal is to improve the evolutionary models by constraining them with the temporal evolution of the central star temperature. In addition the high resolution spectral observations obtained by X-shooter and ALMA show the temporal evolution of the different morphological components.