The identification of the optical companion to the binary millisecond pulsar J0610-2100 in the Galactic field

We have used deep V and R images acquired at the ESO Very Large Telescope to identify the optical companion to the binary pulsar PSR J0610-2100, one of the black-widow millisecond pulsars recently detected by the Fermi Gamma-ray Telescope in the Galactic plane. We found a faint star (V~26.7) nearly coincident (\delta r ~0".28) with the pulsar nominal position. This star is visible only in half of the available images, while it disappears in the deepest ones (those acquired under the best seeing conditions), thus indicating that it is variable. Although our observations do not sample the entire orbital period (P=0.28 d) of the pulsar, we found that the optical modulation of the variable star nicely correlates with the pulsar orbital period and describes a well defined peak (R~25.6) at \Phi=0.75, suggesting a modulation due to the pulsar heating. We tentatively conclude that the companion to PSR J0610-2100 is a heavily ablated very low mass star (~ 0.02Msun) that completely filled its Roche Lobe.Comment: 17 pages, 5 figures - Accepted for pubblication in Ap

Pulsar Timing with the Parkes Radio Telescope for the Fermi Mission

We report here on two years of timing of 168 pulsars using the Parkes radio telescope. The vast majority of these pulsars have spin-down luminosities in excess of 10^34 erg/s and are prime target candidates to be detected in gamma-rays by the Fermi Gamma-Ray Space Telescope. We provide the ephemerides for the ten pulsars being timed at Parkes which have been detected by Fermi in its first year of operation. These ephemerides, in conjunction with the publicly available photon list, can be used to generate gamma-ray profiles from the Fermi archive. We will make the ephemerides of any pulsars of interest available to the community upon request. In addition to the timing ephemerides, we present the parameters for 14 glitches which have occurred in 13 pulsars, seven of which have no previously known glitch history. The Parkes timing programme, in conjunction with Fermi observations, is expected to continue for at least the next four years.Comment: Accepted for publication in PASA.12 page

Establishing a high‐resolution stratigraphy in the Holocene marine sequence of the ancient Theodosian harbor of Istanbul with the help of dendrochronology

Salvage excavations in the Theodosian harbor (Yenikapi-Istanbul) have uncovered diverse archaeological objects including 36 shipwrecks and various Byzantine period wooden docks. The sequence of these docks provided a unique opportunity to obtain a high-resolution stratigraphy. The new approach is based on stratigraphic interpretation of deformation patterns created by the posts in soft sediments, combined with dendrochronological dating of the posts. Dendrochronology offers the potential to date the posts to within one calendar year of felling, a level of precision and accuracy rare in sedimentological analysis. The posts, most of them Quercus, were rammed during six different time periods. The first period is associated with posts cut in 528 AD. The second and third periods are dated by posts cut in 583 and 594 AD, respectively. The fourth-period dates within 8-10 years of 639 AD. The fifth period could be dated only roughly to between 690 and 770 AD. The last period produced a possible placement of after 778 AD. This new approach helps to establish a high-resolution stratigraphy. Furthermore, it provides information about sedimentation history and specific anthropogenic events

The effects of trade wars between us and china on the financial performances of the companies

Tariffs that the USA has implemented in some products toward China have recently caused trade wars. Trump, who was elected US president in 2016, triggered trade wars due to his protectionist attitude towards China. That’s why trade wars officially started in 2018. This attitude of Trump influenced also the stock exchanges of the two countries as well as the trade relations of the two major economies. While our study provides information about the US-China trade wars, it empirically tested the relationship of this war with the stock markets of both countries. The relationship between exports made mutually by the USA and China and the stock exchange is analyzed using the Engle-Granger cointegration method. In this study, which was used monthly data for the period 2016–2019, a long-term relationship between exports and stock market is detected for both countries. Considering the global economy within the framework of this relationship, it is seen important that the two countries withdraw commercial wars and go for an agreement