Some recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).

Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.

The key point of studying AXPs/SGRs (anomalous X-ray pulsars/soft gamma-ray repeaters) is relevant to the energy budget. Historically, rotation was thought to be the only free energy of pulsar until the discovery of accretion power in X-ray binaries. AXPs/SGRs could be magnetars if they are magnetism-powered, but would alternatively be quark-star/fallback-disk systems if more and more observations would hardly be understood in the magnetar scenario.

The transiting exoplanetary system HAT-P-24 was observed by using CCD cameras at Yunnan Observatory and Hokoon Astronomical Centre, China in 2010 and 2012. Three new transit light curves are analyzed by means of MCMC technique, and the new physical parameters of the system are derived, which are compatible with the old ones in the discovery paper. The orbital period of HAT-P-24b is refined and no obvious TTV signal can be found from five transit events during 2010-2012.

The prolonged period of solar minimum between cycles 23 and 24 has invoked a great deal of interest to understand the origin of the unusually low solar activity. Even though the origin of solar activity is believed to lie in the shear layer at the base of the convection zone, the analysis of helioseismic data seem to orientate us toward the near surface. In this context, we analyze the signature of the quasi-biennial periodicity seen in the oscillation frequencies which may provide additional constraints on the solar dynamo models.

We have obtained high-resolution F110W (~ J) and F160W (~ H) band observations of ten submillimeter galaxies (SMGs) with the Hubble Space Telescope's NICMOS camera, in order to resolve their rest-frame optical morphologies, determine the existence of multiple-component, merger-like configurations, and estimate their stellar masses. The selected targets have redshifts in the range 2.2≤ z ≤ 2.81 confirmed with millimeter or mid-IR spectroscopy, guaranteeing that the two bands sample the galaxies' rest-frame optical light with the Balmer break falling between them.

Solar jets are typical proxies of small-scale magnetic reconnection events in the solar atmosphere. In this paper, we observe a small-scale jet in a solar quiet region, using data from SDO/Atmospheric Imaging Assembly (AIA), Helioseismic and Magnetic Imager (HMI), with supplemental data from STEREO/EUVI. From HMI magnetograms and calculated photospheric flows, we find that the jet is related to the interaction between unipolar network fields and emerging internetwork bipoles at the boundary of a supergranular cell. In AIA extreme-ultraviolet images, the jet actually includes two successive plasma ejections along different directions. The first ejection follows a distorted path which guides plasma into a small filament channel nearby. However, the second one shot straight along another direction that is parallel with extrapolated potential magnetic field lines on the local. According to these observations, we advocate that during the jet eruption new emerging magnetic fields are reconnecting at the edge of the supergranular cell with different kinds of ambient fields from low (magnetic canopy) to high (high-reaching loops) to allow the occurrence of successive ejections along different directions.

During an active star formation phase, it is conceivable that the turbulent level of a galaxy increases and consequently an increase in magnetic field by turbulent dynamo process. We point out that the thickness of the dynamo region is sensitive to the turbulent level. We examine the linear growth rate of three different dynamos, namely, αω, α2ω and α2 dynamos. We find that the dependence of the growth rate on turbulent level is quite different for different dynamos. Moreover, the growth rate is not necessary monotonic to turbulence level even in the linear regime.

Lyman-α emitting (LAE) galaxies observed at intermediate to high redshift have the correct size, mass, star formation rate, metallicity, and space density to have been the formation sites of metal-poor globular clusters. LAEs are typically small galaxies with transient starbursts. They should accrete onto spiral and elliptical galaxies over time, delivering metal-poor clusters into the larger galaxies' halos as they themselves get dispersed by tidal forces. The galaxy WLM is a good example of a dwarf remnant from a very early starburst that contains a metal-poor globular cluster but failed to get incorporated into the Milky Way or M31 because of its remote location in the local group.

The distribution of overall education and culture among the population in Latin America and the Caribbean has a very wide range; this is also the case for astronomical engagement. The route to follow in the strategic plan needs to address this situation, for the different levels of development. In particular, guidelines should be established for the regional node(s) where achievable goals should be set up and evaluated periodically. I present a set of ideas on this subject.

Eclipsing binaries are powerful tools for determining the fundamental parameters of stars and, therefore, for measuring accurate, independent distances to nearby galaxies. I present distance measurements that are in progress based on early-type eclipsing binary systems in several Local Group galaxies at a range of metallicities, and discuss the strengths of the method, the limitations and possible sources of systematic error. The goal is to establish several local stepping stones along the extragalactic distance ladder, which will help calibrate the Cepheid period–luminosity relation and thus resolve the ongoing controversy about the distance scale, with its ramifications for cosmology and stellar ages.

Type Ia supernovae (SNe Ia) are the best cosmological distance indicator, however, there is still no agreement on the nature of their progenitors. There are mainly two progenitor scenarios, i.e., the single degenerate (SD) and double degenerate (DD) scenarios. In this article, we introduced our binary evolution models of various progenitor scenarios. We also obtained many properties of the surviving companions from various SD systems, which may be helpful for identifying SN Ia progenitor model. At present, it seems likely that more than one progenitor model may be required to explain the observed diversity of SNe Ia.

We perform the submillimeter/millimeter observations in CO lines toward the southeast of SNR G59.5+0.1 with the KOSMA 3m-Telescope, which fully covers the open cluster NGC 6823. Three molecular clumps are identified in the CO molecular arc, each clump show outflow in motion. The age of the SNR is 8.6×104 yr. The number of selected YSOs are significantly enhanced in the interacting regions, indicating the presence of some recently formed stars.

The location of the white dwarf cooling sequence in the colour–magnitude diagram of simple stellar populations, the magnitude of the red clump and the magnitude of the asymptotic giant branch clump are three stellar distance indicators based on advanced evolutionary phases of low-mass stars. With the present observational capabilities, they can be applied to reach distances ranging from the Galactic disk and halo populations, to galaxies within the Local Group. Techniques devised to exploit these distance indicators are presented, together with a discussion of their calibration and the main sources of systematic errors. A first semi-empirical calibration of the asymptotic giant branch absolute magnitude in both the I and K bands is also derived.

We examine to what extent the inferred surface temperature of magnetars in quiescence can constrain the presence of a superfluid in the neutron star core and the role of magnetic field decay in the core. By performing detailed simulations of neutron star cooling, we show that extremely strong heating from field decay in the core cannot produce the high observed surface temperatures nor delay the onset of neutron superfluidity in the core. We find that it is not possible to conclude that magnetar cores are in a non-superfluid state purely from high surface temperatures. We find that neutron superfluidity in the core occurs less than a few hundred years after neutron star formation for core fields < 1016 G. Thus all known neutron stars, including magnetars, without a core containing exotic particles, should have a core of superfluid neutrons and superconducting protons.

General relativity has predicted the existence of gravitational waves (GW), which are waves of the distortions of space-time with two degrees of polarization and the propagation speed of light. Alternative theories predict more polarizations, up to a maximum of six, and possible frequency dependent propagation speed from the light speed. The polarization and dispersion properties of GWs shed light on the spin and mass information of gravitons. Although GWs have not been directly detected yet, their amplitude upper-bounds has been addressed by research using different types of detectors. For example, the amplitude upper-bounds for the stochastic background derived from pulsar timing observations have already become astrophysically interesting. The present paper reviews proposals to test the gravity theories in the radiation regime by observing GWs using pulsar timing arrays. We also present the estimation for the upper-bounds on the amplitude of alternative modes for the stochastic background of GW.

We investigate the changes in polarization position angle in radiation from pulsar A around the eclipse in the Double Pulsar system PSR J0737-3039A/B at the 20 cm and 50 cm wavelengths using the Parkes 64-m radio telescope. The changes are ~ 2σ during and shortly after the eclipse at 20 cm but less significant at 50 cm. We show that the changes in position angle during the eclipse can be modelled by differential synchrotron absorption in the eclipse regions. Position angle changes after the eclipse are interpreted as Faraday rotation in the magnetotail of pulsar B. Implied charge densities are consistent with the Goldreich-Julian density, suggesting that the particle energies in the magnetotail are mildly relativistic.

In this work we discuss the turbulent evolution of structures in the intracluster medium based on the two fluid approximations: MHD and collisionless plasma under Chew Goldberger Low (CGL) closure. Turbulence excited by galactic motions and gas inflow in intracluster medium will develop in very different ways considering the two fluid approaches. Statistics of density distributions, and velocity and magnetic fields are provided. Compared to the standard MHD case, the instabilities that arise from CGL-MHD models strongly modify the probability distribution functions of the plasma velocity and density, basically increasing their dispersion. Moreover, the spectra of both density and velocity show increased power at small scales, due to the instabilities growth rate that are larger as smaller scales. Finally, in high beta plasmas, i.e. B2 << P, a fast increase of the magnetic energy density is observed in the CGL-MHD models, faster than the standard MHD turbulent dynamo that operates at timescales τ ~ L/vL. The signatures of the increased power at small scales and the increase of magnetic field intensity from CGL-MHD models could be observed at radio wavelengths. A comparison of the structure function of the synchrotron emission, as well as the statistics of Faraday rotation effects on the synchrotron polarization, for both the MHD and CGL-MHD models is provided.

Pulsars are arguably the only astrophysical sources whose emission spans the entire electromagnetic spectrum, from decameter radio wavelengths to TeV energies. The LOw Frequency ARray (LOFAR) offers the unique possibility to study pulsars over a huge fractional bandwidth in the bottom 4 octaves of the radio window, from 15–240 MHz. Here we present a LOFAR study of pulsar single pulses, focussing specifically on the bright nearby pulsar B0809+74. We show that the spectral width of bright low-frequency pulses can be as narrow as 1 MHz and scales with increasing frequency as Δ f/fc ~ 0.15, at least in the case of the PSR B0809+74. This appears to be intrinsic to the pulsar, as opposed to being due to propagation effects. If so, this behavior is consistent with predictions by the strong plasma turbulence model of pulsar radio emission. We also present other observed properties of the single pulses and discuss their relation to other single-pulse phenomena like giant pulses.

Shortly after the discovery of PSR J1906+0746, some hints of profile variations were already interpreted as first signs of relativistic spin-precession occuring. Using observations from the Nançay, Arecibo and Green Bank Radio Observatories, we report here the measurement of pulse profile and polarimetric variations. Using the Rotating Vector Model, we show that PSR J1906+0746 is likely to be an orthogonal rotator (α ≃ 80°). Fitting our polarimetric data to a precession model, we determined the geometry of the pulsar and found a wide misalignment angle (δ = 89−44+85 deg, 95% C.L.), although the uncertainty is large. Assuming this geometry, we constructed the beam maps of both magnetic poles.

We propose a mechanism that contributes energy and particles to the diffuse x-ray halos of galaxies and clusters, based on the dark quantum states of large-scale gravity wells.