Photometric redshifts as a tool to study the Coma cluster galaxy populations

We investigate the Coma cluster galaxy luminosity function (GLF) at faint magnitudes, in particular in the u* band by applying photometric redshift techniques applied to deep u*, B, V, R, I images covering a region of ~1deg2 (R 24). Global and local GLFs in the B, V, R and I bands obtained with photometric redshift selection are consistent with our previous results based on a statistical background subtraction. In the area covered only by the u* image, the GLF was also derived after applying a statistical background subtraction. The GLF in the u* band shows an increase of the faint end slope towards the outer regions of the cluster (from alpha~1 in the cluster center to alpha~2 in the cluster periphery). This could be explained assuming a short burst of star formation in these galaxies when entering the cluster. The analysis of the multicolor type spatial distribution reveals that late type galaxies are distributed in clumps in the cluster outskirts, where X-ray substructures are also detected and where the GLF in the u* band is steeper.Comment: 14 pages, 2 figures in jpeg format, accepted in A&

An alternate approach to measure specific star formation rates at 2<z<7

We trace the specific star formation rate (sSFR) of massive star-forming galaxies ($\gtrsim\!10^{10}\,\mathcal{M}_\odot$) from $z\sim2$ to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We show the reliability of this approach by means of semi-analytical and hydrodynamical cosmological simulations. We then apply it to real data, using the SMFs derived in the COSMOS and CANDELS fields. We find that the sSFR is proportional to $(1+z)^{1.1\pm0.2}$ at $z>2$, in agreement with other observations but in tension with the steeper evolution predicted by simulations from $z\sim4$ to 2. We investigate the impact of several sources of observational bias, which however cannot account for this discrepancy. Although the SMF of high-redshift galaxies is still affected by significant errors, we show that future large-area surveys will substantially reduce them, making our method an effective tool to probe the massive end of the main sequence of star-forming galaxies.Comment: ApJ accepte

Reconstructing the galaxy density field with photometric redshifts: II. Environment-dependent galaxy evolution since z≃3z \simeq 3

Although extensively investigated, the role of the environment in galaxy formation is still not well understood. In this context, the Galaxy Stellar Mass Function (GSMF) is a powerful tool to understand how environment relates to galaxy mass assembly and the quenching of star-formation. In this work, we make use of the high-precision photometric redshifts of the UltraVISTA Survey to study the GSMF in different environments up to $z \sim 3$, on physical scales from 0.3 to 2 Mpc, down to masses of $M \sim 10^{10} M_{\odot}$. We witness the appearance of environmental signatures for both quiescent and star-forming galaxies. We find that the shape of the GSMF of quiescent galaxies is different in high- and low-density environments up to $z \sim 2$ with the high-mass end ($M \gtrsim 10^{11} M_{\odot}$) being enhanced in high-density environments. On the contrary, for star-forming galaxies a difference between the GSMF in high- and low density environments is present for masses $M \lesssim 10^{11} M_{\odot}$. Star-forming galaxies in this mass range appear to be more frequent in low-density environments up to $z < 1.5$. Differences in the shape of the GSMF are not visible anymore at $z > 2$. Our results, in terms of general trends in the shape of the GSMF, are in agreement with a scenario in which galaxies are quenched when they enter hot gas-dominated massive haloes which are preferentially in high-density environments.Comment: 18 pages, 10 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

The Effect of Murottal and Music Therapy on Reducing Blood Pressure in Palimanan Climbon

Complementary therapies in both music and murottal therapy are beleaved effective because the songs and Quranic verses can have a therapeutic effect through the mind and physiology of human. This study was to identify differences influence of murotal therapy and music therapy in lowering blood pressure, This study used a quasi-experimental with a pretest-posttest approach design. The sample used in this study were 30 respondents who are divided into 2 intervention groups, group 1used murottal and group 2 terpy murottal used music therapy in hypertensive patients in Kepuh village of used Rw 04 and 05 Palimanan Cirebon sampling technique cluster rondom sampling. Statistical tests using t test. Results of data analysis showed there is significantdifferencebetweenthebloodpressureaftermurottaltherapywiththeblood pressure after music therapy in hypertensive patients, whith p value 0,001. Age and genderfactorsareconsideredhaveinfluenceinloweringbloodpressureaftermurottal therapy. The results of this study are expected to be the basis of complementary therapies and can be implemented as independent and innovative interventions in the nursing care of patients with hypertension

Pre-marital Sexual Behaviour in Student Dating: A Literature Review

Students are often sexually active, but many of them delay their marriage to reach their education goals. This literature review aims to describe about premarital sexual behavior in students dating. The data was collected by Public media database with keywords:“Sexual Behaviour, Pre-marital, Student”. The inclusion criteria were students, with a romantic partner who had engaged in sexual activity, available free full text, qualitative study and published between 2014-2020. From 8 eligible journals met these criteria in the Public media database. The research indicates 7 themes concerning premarital sexual behaviour: love, disregard for virginity, considering pre-marital sex as normal, or a human right and sign of maturity, peer pressure, supporting a successful marriage, innate instinct. However, pre-marital sexual behavior can increase the risk of HIV and other sexual diseases. Hence, it is important for health workers to actively educate adolescents about reproductive health and pre-marital sex. &nbsp; Keywords: Pre-marital, Sexual Behaviour, Student, Datin

On the nature of faint Low Surface Brightness galaxies in the Coma cluster

This project is the continuation of our study of faint Low Surface Brightness Galaxies (fLSBs) in one of the densest nearby galaxy regions known, the Coma cluster. Our goal is to improve our understanding of the nature of these objects by comparing the broad band spectral energy distribution with population synthesis models. The data were obtained with the MEGACAM and CFH12K cameras at the CFHT. We used the resulting photometry in 5 broad band filters (u*, B, V, R, and I), that included new u*-band data, to fit spectral models. With these spectral fits we inferred a cluster membership criterium, as well as the ages, dust extinctions, and photometric types of these fLSBs. We show that about half of the Coma cluster fLSBs have a spectral energy distribution well represented in our template library while the other half present a flux deficit at ultraviolet wavelengths. Among the well represented, ~80% are probably part of the Coma cluster based on their spectral energy distribution. They are relatively young (younger than 2.3 Gyrs for 90% of the sample) non-starburst objects. The later their type, the younger fLSBs are. A significant part of the fLSBs are quite dusty objects. fLSBs are low stellar mass objects (the later their type the less massive they are), with stellar masses comparable to globular clusters for the faintest ones. Their characteristics are correlated with infall directions, confirming the disruptive origin for part of them.Comment: Accepted for publication in A&A, 10 pages, 10 figure

The Redshift Distribution of Giant Arcs in the Sloan Giant Arcs Survey

We measure the redshift distribution of a sample of 28 giant arcs discovered as a part of the Sloan Giant Arcs Survey (SGAS). Gemini/GMOS-North spectroscopy provides precise redshifts for 24 arcs, and "redshift desert" constraints for the remaining four. This is a direct measurement of the redshift distribution of a uniformly selected sample of bright giant arcs, which is an observable that can be used to inform efforts to predict giant arc statistics. Our primary giant arc sample has a median redshift z=1.821 and nearly two thirds of the arcs - 64% - are sources at z \gtrsim 1.4, indicating that the population of background sources that are strongly lensed into bright giant arcs resides primarily at high redshift. We also analyze the distribution of redshifts for 19 secondary strongly lensed background sources that are not visually apparent in SDSS imaging, but were identified in deeper follow-up imaging of the lensing cluster fields. Our redshift sample for the secondary sources is not spectroscopically complete, but combining it with our primary giant arc sample suggests that a large fraction of all background galaxies which are strongly lensed by foreground clusters reside at z \gtrsim 1.4. Kolmogorov-Smirnov (KS) tests indicate that our well-selected, spectroscopically complete primary giant arc redshift sample can be reproduced with a model distribution that is constructed from a combination of results from studies of strong lensing clusters in numerical simulations, and observational constraints on the galaxy luminosity function.Comment: eapj format, 6 Pages, 2 Figures, 2 Tables. Published in ApJ Letter