New Galactic Planetary Nebulae selected by radio and multi-wavelength characteristics

We have used the Cornish radio catalogue combined with the use of multi-wavelength data to identify 62 new Planetary Nebula (PN) candidates close to the Galactic mid-plane. Of this sample 11 have weak optical counterparts in deep narrow band H$\alpha$ imaging that allows their spectroscopic follow-up. We have observed eight of these candidates spectroscopically, leading to the confirmation of 7 out of 8 as PNe. All but one of our sample of newly detected PNe appear to be of Type I chemistry with very large [NII]/H$\alpha$ ratios. This indicates that our selection method heavily favours detection of this kind of PN. Cornish is a low Galactic latitude survey where young objects and Type I PNe (thought to derive from higher mass progenitors) are more plentiful, but where optical extinction is large. The very high success rate in correctly identifying PNe in this zone proves the efficacy of our radio and multiple multi-wavelength diagnostic tools used to successfully predict and then confirm their PN nature, at least in the cases where an optical counterpart is found and has been observed. The study reinforces the effective use of a combination of multi-wavelength and optical data in the identification of new Galactic PNe and especially those of Type I chemistries whose dusty environments often prevents their easy detection in the optical regime alone.Comment: 13 pages, 5 figure

The temporal analysis of light pollution in Turkey using VIIRS data

© 2021, The Author(s), under exclusive licence to Springer Nature B.V.Artificial Light pollution (AL) in Turkey and in Turkish observatories between 2012–2020 have been studied using the archival data of Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. The astroGIS database has been used in processing the data (astrogis.org) Aksaker et al. (2020a). The total energy released to space from Turkey increased by 80% in 2019 with respect to 2012. In the span of the dataset, a steady and continuous increase has been observed throughout all cities of the country. On the other hand, Dark Sky Park locations, East and Southeast Anatolian regions and mostly rural areas around the cities kept their AL level constant. Four demographic parameters have been studied and they were found to be correlated very well with AL: Population (R≃ 0.90); GDP (R≃ 0.87); Total Power Consumption (R≃ 0.66) and Outdoor Lightening (R≃ 0.67). Contrary to countries acting to prevent AL increases, Turkey seems to be at the beginning of an era where AL will arithmetically increase throughout the country and enormous amount of energy will continuously escape to space and therefore will be wasted. Therefore, a preventive legislation, especially for invaluable astronomical site locations such as TURAG, TUG, DAG and ÇAAM where each is counted as a truly dark site due to their SQM values, has to be enacted in Turkey, in very near future

Astronomical Site Selection for Turkey Using GIS Techniques

A site selection of potential observatory locations in Turkey have been carried out by using Multi-Criteria Decision Analysis (MCDA) coupled with Geographical Information Systems (GIS) and satellite imagery which in turn reduced cost and time and increased the accuracy of the final outcome. The layers of cloud cover, digital elevation model, artificial lights, precipitable water vapor, aerosol optical thickness and wind speed were studied in the GIS system. In conclusion of MCDA, the most suitable regions were found to be located in a strip crossing from southwest to northeast including also a diverted region in southeast of Turkey. These regions are thus our prime candidate locations for future on-site testing. In addition to this major outcome, this study has also been applied to locations of major observatories sites. Since no goal is set for \textit{the best}, the results of this study is limited with a list of positions. Therefore, the list has to be further confirmed with on-site tests. A national funding has been awarded to produce a prototype of an on-site test unit (to measure both astronomical and meteorological parameters) which might be used in this list of locations.Comment: 17 pages, 10 figures, accepted by Experimental Astronom

H alpha measurements using DEFPOS/RTT150 Telescope: Instrumentation and observations

WOS: 000264845000013To investigate the physical properties of HII regions and some PNe about 4' in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RT7150 telescope (f/48) at TUBITAK National Observatory (Antalya/Bakirhtepe, Turkey). The spectrometer has a 4' circular field of view and a velocity resolution of 27.27 km s(-1) (a spectral resolving power of 11 000) over a 200 km s(-1) spectral window near H alpha. This work presents the details of the newly redesigned instrument for coude observations, the data reduction techniques and finally presents some physical results of our new H alpha observations selected from the Reynolds et al. (2005) and Fich et al. (1990) papers. The DEFPOS system has been fully tested and the first observations of HII regions and PNe in the Galaxy are used to illustrate the power of the instrument. We feel that our first Fabry-Perot observations can provide a powerful tool for the study of objects with small angular size. In the future, we are planning to prepare a catalog including some physical properties such as radial velocity, line width, and intensity of some PNe and HII regions close to the 4' field of view.University of Wisconsin; VTSS map; SIMBAD Astronomical Database; Southern H-Alpha Sky Survey Atlas (SHASSA); National Science FoundationNational Science Foundation (NSF); TUBITAK (the Scientific and Technical Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [104T252]The authors would like to thank the TUG staff for help during the observations. The authors also wish to thank R. J. Reynolds, and L. M. Haffner, from the University of Wisconsin for letting us use their data and for having greatly contributed to the start of this study. We acknowledge the use of the VTSS map, a wide-field image survey of the Galaxy's warm ionized interstellar medium, the use of the SIMBAD Astronomical Database, operated at CDS, Strasbourg, France and the use of the Southern H-Alpha Sky Survey Atlas (SHASSA), which is supported by the National Science Foundation. This work is supported by TUBITAK (the Scientific and Technical Research Council of Turkey) with grant number 104T252

Emission Lines of Northern Planetary Nebulae

In this work, we present results of long slit spectrophotometric emission line flux observations of selected planetary nebulae (PNe). We have measured absolute fluxes and equivalent widths (EW) of all observable emission lines. In addition to these observations, electron temperatures (Te), densities (Ne), and chemical abundances were also calculated. The main purpose of this work is to fill the gaps in emission line flux standards for the northern hemisphere. It is expected that the measured fluxes would be used as standard data set for further photometric and spectrometric measurements of HII regions, supernova remnants etc

A search for optical counterparts of ULX-4 in M51 galaxy

We report on the identi cation of the optical counterparts of ve out of seven Ultraluminous X-ray&nbsp;Sources (ULXs) in NGC 4490/4485 galaxy pair. Using archival Hubble Space Telescope (HST) imaging&nbsp;data, we identi ed unique optical counterparts for three ULXs (X-3, X-4 and X-7) and three candidate&nbsp;counterparts for the other two ULXs (X-2 and X-6) within 0:0015 error radius. Of the two remaining&nbsp;ULXs, X-1 has no HST imaging data and photometry could not be performed due to the position ofX-5 in NGC4490. Absolute magnitudes (MV ) of the optical counterparts lie between ??6:3 and ??3:7.&nbsp;Color-Magnitude Diagrams (CMDs) have been used to investigate the properties of counterparts and&nbsp;their environments. The location of the counterparts of X-2, X-4, and X-6 suggest possible association&nbsp;with nearby group of stars while others have no association with a star cluster or a group of stars. For&nbsp;comparison purposes, we analyzed previously unused three archival XMM-Newton observations. The&nbsp;long-term X-ray light curve of the sources (except transient X-7) shows variability by a factor of threein a time scale more than a decade. The use of disk blackbody (DISKBB) model for the mass of the&nbsp;compact objects indicates that these objects to be most likely in the range 10??15 M .</p

Outward FDI and the investment development path of a late-industrialising economy Evidence from Ireland

Includes bibliographical referencesAvailable from British Library Document Supply Centre- DSC:9350. 10306(01/08) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

The ULX source X-3 in NGC 4258: A search for its X-ray and optical properties

© 2020 The Author(s).We present the results of a search for the nature of ultraluminous X-ray source (ULX) X-3 in the nearby galaxy NGC 4258. We use archival data from XMM-Newton, Chandra, NuSTAR, and Hubble Space Telescope (HST) observations. Total X-ray data were analysed to find that the model parameters of the system are indicative of a stellar-mass black hole, ∼10 M⊙, as the central compact object. Furthermore, analyses of the optical data from HST reveal two optical candidates at 90 per cent confidence level within an error radius of 0.28 arcsec. Assuming the optical emission is dominated by the donor star, both of these candidates are found to have spectral types that lie between B3 and F1 with absolute magnitudes of MV ≈ -6.4. Moreover, the age and mass estimates for the candidates are found to be 10 and 18 Myr and 13 and 20 M⊙, respectively

A Study on W Ursae Majoris-Type Systems Recognised by the ROTSE-IIId Experiment

We present a study on characterising the light curves of W UMa-type systems gathered from the archive containing 5 years of data observed with the Robotic Optical Transient Search Experiment Telescope (ROTSE-IIId) located in Turkey. A sample of 45 W UMa-type systems was studied on the basis of Fourier decomposition of light curves and some basic geometrical parameters, namely degree of contact (f), mass ratio (q), and orbital inclination (i), as approximated values for these systems were determined. Moreover, methods based on the Fourier transform technique were applied to the discrete data to determine the orbital periods of those systems. Preliminary estimates for the system parameters were presented and compared with the values available in the literature