Andromeda [1] is a proof assistant for dependent type theory with equality reflection following the tradition of Edinburgh LCF [3]: (1) there is an abstract datatype of type-theoretic judgments whose values can only be constructed by a small nucleus, and (2) the user interacts with the nucleus by writing programs in a high-level, statically typed Andromeda meta-language (AML). The only part of ...

The important, lasting result of Fritz Zwicky’s early paper on extragalactic astrophysics, which is not mentioned in the abstract, is his conclusion, derived in Sect. 5, that the universe contains much more dark than luminous matter. This result is embedded in a review of what was known about “nebulae” and their redshift in 1933. The first methods to determine distances of galaxies and their di...

The important, lasting result of Fritz Zwicky’s early paper on extragalactic astrophysics, which is not mentioned in the abstract, is his conclusion, derived in Sect. 5, that the universe contains much more dark than luminous matter. This result is embedded in a review of what was known about “nebulae” and their redshift in 1933. The first methods to determine distances of galaxies and their di...

The chemical evolution history of a galaxy hides clues about how it formed and has been changing through time. We have studied the chemical evolution history of the Milky Way (MW) and Andromeda (M31) to find which are common features in the chemical evolution of disc galaxies as well as which are galaxy-dependent. We use a semi-analytic multi-zone chemical evolution model. Such models have succ...

We present UBV I CCD photometry of the stellar contents and globular cluster(GC) candidates in the spiral galaxy NGC 300 in the Sculptor group. Color-magnitude diagrams for 18 OB associations having more than 30 member stars are presented. The slope of the initial mass function for the bright stars in NGC 300 is estimated to be Γ = −2.6±0.3. Assuming the distance to NGC 300 of (m−M)0 = 26.53± 0...

We present UBV I CCD photometry of the stellar contents and globular cluster(GC) candidates in the spiral galaxy NGC 300 in the Sculptor group. Color-magnitude diagrams for 18 OB associations having more than 30 member stars are presented. The slope of the initial mass function for the bright stars in NGC 300 is estimated to be Γ = −2.6±0.3. Assuming the distance to NGC 300 of (m−M)0 = 26.53± 0...

Spectroscopic abundance determinations for stars spanning a Hubble time in age are necessary in order to unambiguously determine the evolutionary histories of galaxies. Using FORS1 in Multi-Object Spectroscopy mode on ANTU (UT1) at the ESO-VLT on Paranal we obtained near infrared spectra from which we measured the equivalent widths of the two strongest Ca II triplet lines to determine metal abu...

We have obtained spectra of three QSO/AGNs with the GHRS aboard the Hubble Space Telescope to search for absorption from low column density gas in the halo of the dwarf spheroidal (dSph) galaxy Leo I. The probe sight lines pass 2.1, 3.7, and 8.1 kpc from the center of the galaxy, but no C IV, Si II, or Si IV absorption is found at the velocity of Leo I. The absence of low-ionization species sug...

We present sensitive molecular line observations of the metal-poor blue compact dwarf I Zw 18 obtained with the IRAM Plateau de Bure interferometer. These data constrain the CO J = 1 → 0 luminosity within our 300 pc (FWHM) beam to be LCO < 1×10 5 K km s pc (ICO < 1 K km s ), an order of magnitude lower than previous limits. Although I Zw 18 is starbursting, it has a CO luminosity similar to or ...