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When the Universe was just 3 billion years old, half of the most massive galaxies had already ceased star formation, and such a galaxy has now been observed using gravitational lensing, unexpectedly turning out to be a compact, fast-spinning disk galaxy rather than a proto-bulge galaxy.

We discuss two new observational techniques that use observations of the cosmic microwave background (CMB) to place constraints on the mass, distance, and size distribution of small objects in the Kuiper Belt and inner Oort Cloud, collectively known as trans-Neptunian objects (TNOs). The first new technique considers the spectral distortion of the isotropic, or monopole, CMB by TNOs that have been heated by solar radiation to temperatures above that of the CMB. We apply this technique to the spectral measurements of the CMB by the Far Infrared Absolute Spectrophotometer on the Cosmic Background Explorer. The second technique utilizes the change in amplitude of the TNO signal due to the orbital motion of the observer to separate the TNO signal from the invariant extragalactic CMB and construct a map of the mass distribution in the outer solar system. We estimate the ability of future CMB experiments to create such a map.

We use the strong nebular emission lines of O III, ll5007 and 4959, to set a robust upper limit on the time dependence of the fine-structure constant. We find img1.gif < 2 x 10-13 yr-1, corresponding to Da/a(0) = img2.gif x 10-4 for quasars with 0.16 < z < 0.80 obtained from the SDSS Early Data Release. Using a blind analysis, we show that the upper limit given here is invariant with respect to 17 different ways of selecting the sample and analyzing the data. As a by-product, we show that the ratio of transition probabilities corresponding to the ll5007 and 4959 lines is 2.99 +- 0.02, in good agreement with (but more accurate than) theoretical estimates. We compare and contrast the O III emission line method used here with the many-multiplet method that was used recently to suggest evidence for a time-dependent a. In an appendix we analyze the quasars from the recently available SDSS Data Release One sample and find Da/a(0) = img3.gif x 10-4.

Telescopes are much more expensive than astronomers, so it is essential to minimize required sample sizes by using the most data-efficient statistical methods possible. However, the most commonly used model-independent techniques for finding the relationship between two variables in astronomy are flawed. In the worst case they can lead without warning to subtly yet catastrophically wrong results, and even in the best case they require more data than necessary. Unfortunately, there is no single best technique for nonparametric regression. Instead, we provide a guide for how astronomers can choose the best method for their specific problem and provide a python library with both wrappers for the most useful existing algorithms and implementations of two new algorithms developed here.

The H$\beta$emission line in a typical Type I quasar is composed of a broad base and a narrow core, with the core velocity characteristic of narrow-line region emission, and line-fitting routines typically assume this picture. We test the effects of removing this constraint, and find a substantial group of Type I quasars in the Sloan Digital Sky Survey catalog with H$\beta$emission line cores broader than 1200 km s$^{-1}$, above the velocity believed possible for gas in the quasar narrow-line region. We identify this group of “anomalous H$\beta$quasars” (AHQs) as a distinct population because of a variety of spectral and photometric signatures common to these AHQs but atypical of other quasars. These features are similar to some aspects of narrow-line Seyfert 1s and correlations identified by Eigenvector 1, but also contain distinct features that make it difficult to classify AHQs. We demonstrate that AHQs comprise at least 11% and most likely approximately one quarter of the SDSS Type I quasar population at 0.2 $<$z$<$0.8. For AHQs, the [O iii]$\lambda$4959, 5007 profile is often better fit by de-linking it from the H$\beta$core, while a more standard linked fit produces a tight correlation between narrow- and broad-line velocities. We find that [O iii] in AHQs sometimes has a standard narrow-line profile and other times matches the H$\beta$core, but is rarely in between the two, implying that the broadened core emission arises from a distinct physical region. Another feature of AHQs is a diminished [O ii] line, which might indicate a connection between AHQs and the interstellar mediums of their host galaxies, through reduced photoionization or star formation. We find that it is difficult to produce AHQs using the current quasar standard model.