We present a comprehensive catalog of high signal-to-noise spectra obtained with the DEIMOS spectrograph on the Keck II telescope for a sample of F850LP<22.43 (AB) field spheroidal (E+S0s; 163) and bulge dominated disk (61) galaxies in the redshift range 0.2 < z < 1.2, selected on the basis of visual morphology from the northern field of the Great Observatories Origins Deep Survey (GOODS-N). We discuss sample selection, photometric properties and spectral reduction. We derive scale-lengths, surface brightnesses and photometric inhomogeneities from the ACS data, and redshifts, stellar velocity dispersions, [O II] and Hδ equivalent widths from the Keck spectroscopy. Using the published 2Ms Chandra X-ray catalog we identify active galactic nuclei to clarify the origin of emission lines seen in the Keck spectra. Only 2/13 [O II] emitting early-type galaxies are identified as secure AGN on the basis of their X-ray emission. Contrary to earlier suggestions, we find that most spheroidals containing 'blue cores' are not associated with non-thermal nuclear activity. We examine 0 Using data obtained with the Hubble Space Telescope operated by AURA for NASA and the W.M. Keck Observatory on Mauna Kea, Hawaii. The W.M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California and NASA and was made possible by the generous financial support of the W.M. Keck Foundation.-2the zero point, tilt and scatter of the Fundamental Plane (FP) as a function of redshift and morphological properties, carefully accounting for luminositydependent biases via Montecarlo simulations. The evolution of the overall FP can be represented by a mean change in effective mass-to-light ratio given by < d log(M/L B )/dz >= −0.72 +0.07−0.05 ± 0.04. However, this evolution depends significantly on the dynamical mass, being slower for larger masses as reported in a previous letter. In addition, we separately show the intrinsic scatter of the FP increases with redshift as d(rms(M/L B ))/dz=0.040 ± 0.015. Although these trends are consistent with single burst populations which formed at z f > 2 for high mass spheroidals and z f ∼ 1.2 for lower mass systems, a more realistic picture is that most of the stellar mass formed in all systems at z > 2 with subsequent activity continuing to lower redshifts (z < 1.2). The fraction of stellar mass formed at recent times depend strongly on galactic mass, ranging from < 1% for masses above 10 11.5 M ⊙ to 20-40% below 10 11 M ⊙ . Independent support for recent activity is provided by spectroscopic ([O II] emission, Hδ) and photometric (blue cores and broad-band colors) diagnostics. Via the analysis of a large sample with many independent diagnostics, we are able to reconcile previously disparate interpretations of the assembly history of field spheroidals. We discuss the implications of this measurement for the determination of the evolution of the number density of E+S0s galaxies, suggesting number density evolution of the morphologically selected ...
We have carried out an empirical study of the seasonal cycle of nitrous oxide (N2O) using the data archived by the National Oceanic and Atmospheric Administration – Climate Monitoring and Diagnostics Laboratory (NOAA‐CMDL) Global Cooperative Air Sampling Network from 1977 to 2000. In order to isolate the seasonal cycle, we first detrended the data using least square polynomial fits. The remaining variability was averaged to extract the seasonal cycle, which has an amplitude of about 0.8 ppbv. The statistical significance of the seasonal signal was established using the multitaper method and Welch's method for power spectrum analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.