Using imaging data from the SDSS survey, we present the g and r radial stellar light distribution of a complete sample of ∼90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles are reliable (1σ uncertainty less than 0.2 mag) down to µ ∼ 27 mag/ 2 . Only ∼10% of all galaxies have a normal/standard purely exponential disk down to our noise limit. The surface brightness distribution of the rest of the galaxies is better described as a broken exponential. About 60% of the galaxies have a break in the exponential profile between ∼1.5-4.5 times the scalelength followed by a downbending, steeper outer region. Another ∼30% shows also a clear break between ∼4.0-6.0 times the scalelength but followed by an upbending, shallower outer region. A few galaxies have even a more complex surface brightness distribution. The shape of the profiles correlates with Hubble type. Downbending breaks are more frequent in later Hubble types while the fraction of upbending breaks rises towards earlier types. No clear relation is found between the environment, as characterised by the number of neighbours, and the shape of the profiles of the galaxies.

We present the evolution of the luminosity-size and stellar massYsize relations of luminous (L V k 3:4 ; 10 10 h À2 70 L) and massive (M Ã k 3 ; 10 10 h À2 70 M) galaxies in the last $11 Gyr. We use very deep near-infrared images of the Hubble Deep FieldYSouth and the MS 1054-03 field in the J s , H, and K s bands from FIRES to retrieve the sizes in the optical rest frame for galaxies with z > 1. We combine our results with those from GEMS at 0:2 < z < 1 and SDSS at z $ 0:1 to achieve a comprehensive picture of the optical rest-frame size evolution from z ¼ 0 to 3. Galaxies are differentiated according to their light concentration using the Sérsic index n. For less concentrated objects, the galaxies at a given luminosity were typically $3 AE 0:5 (AE2) times smaller at z $ 2:5 than those we see today. The stellar massYsize relation has evolved less: the mean size at a given stellar mass was $2 AE 0:5 times smaller at z $ 2:5, evolving proportionally to (1 þ z) À0:40AE0:06. Simple scaling relations between dark matter halos and baryons in a hierarchical cosmogony predict a stronger (although consistent within the error bars) than observed evolution of the stellar massYsize relation. The observed luminosity-size evolution out to z $ 2:5 matches well recent infall model predictions for Milky WayYtype objects. For low-n galaxies, the evolution of the stellar massYsize relation would follow naturally if the individual galaxies grow inside out. For highly concentrated objects, the situation is as follows: at a given luminosity, these galaxies were $2:7 AE 1:1 times smaller at z $ 2:5 (or, put differently, were typically $2:2 AE 0:7 mag brighter at a given size than they are today), and at a given stellar mass the size has evolved proportionally to (1 þ z) À0:45AE0:10 .

Using the combined capabilities of the large near‐infrared Palomar/DEEP‐2 survey, and the superb resolution of the Advanced Camera for Surveys HST camera, we explore the size evolution of 831 very massive galaxies (M⋆≥ 1011h−270 M⊙) since z∼ 2. We split our sample according to their light concentration using the Sérsic index n. At a given stellar mass, both low (n < 2.5) and high (n > 2.5) concentrated objects were much smaller in the past than their local massive counterparts. This evolution is particularly strong for the highly concentrated (spheroid like) objects. At z∼ 1.5, massive spheroid‐like objects were a factor of 4 (±0.4) smaller (i.e. almost two orders of magnitudes denser) than those we see today. These small sized, high‐mass galaxies do not exist in the nearby Universe, suggesting that this population merged with other galaxies over several billion years to form the largest galaxies we see today.

We measure the sizes of 82 massive ( ) galaxies at utilizing deep HST NICMOS datataken in the GOODS North and South fields. Our sample is almost an order of magnitude larger than previous studies at these redshifts, providing the first statistical study of massive galaxy sizes at , confirming the z 1 2 extreme compactness of these systems. We split our sample into disk-like ( ) and spheroid-like ( ) n ≤ 2 n 1 2 galaxies based on their Sérsic indices, and find that at a given stellar mass disk-like galaxies at are a z ∼ 2.3 factor of 2.6 ‫ע‬ 0.3 smaller than present-day equal-mass systems, and spheroid-like galaxies at the same redshifts are 4.3 ‫ע‬ 0.7 smaller than comparatively massive elliptical galaxies today. At our results are compatible z 1 2 with both a leveling off, or a mild evolution in size. Furthermore, the high density (∼2 # 10 10 M kpc ) of Ϫ3 , massive galaxies at these redshifts, which are similar to present-day globular clusters, possibly makes any further evolution in sizes beyond unlikely. z p 3