Based on the context

Mike

The problem is that 'arpegiado continuo' is a set; the adjective in this case is sustained. Musical Cathedral Organ Sustained Arpeggio | Sound Effects ...
24 Feb 2009 ... Musical Cathedral Organ Sustained Arpeggio. Sound Effects and Royalty Free Sound Effects for Creative Audio Visual Projects Including ...
www.audiomicro.com/musical-cathedral-organ-sustained-arpegg... - En caché

Arpeggiated is quite common

Johannes Brahms - 4 Lieder, Op.96 - Classical Archives
Brahms illustrates the rocking of the boat with an arpeggiated accompaniment. At the mention of the dance music, it turns into an ironic "vamp" evoking a ...
www.classicalarchives.com/work/172806.html - Cached - Similar
DUPARC: Songs
Sérénade 1 sets words by Gabriel Marc with an arpeggiated accompaniment that suggests something of the earlier work of Fauré. The group of five songs, ...
www.naxos.com/mainsite/blurbs_reviews.asp?item...8... - Cached
FJHmusic.com | Piano Music | Written for You Piano Solos | Melody ...
Sunset Serenade is a lyrical piece which presents a chordal melody with an arpeggiated accompaniment. It's perfect for the intermediate student who is ...
www.fjhmusic.com › ... › Written for You › Melody Bober - Cached - Similar
OPERA NEWS - Mareike Morr: "Lamenti: Furore e Diletti"
These include two gems from from Vivaldi's last Roman opera, Il Giustino, "Sento in seno," with striking arpeggiated accompaniment, and the pensive "Vedrò ...
www.operanews.com/operanews/templates/content.aspx?id=19062 - Cached


ar·peg·gi·o
   [ahr-pej-ee-oh, -pej-oh] Show IPA
–noun, plural -gi·os. Music .
1.
the sounding of the notes of a chord in rapid succession instead of simultaneously.
2.
a chord thus sounded.
.
Make Google Your Homepage

Also called broken chord.

Origin:
1735–45; < Italian: literally, a harping, noun derivative of arpeggi ( are ) to play on the harp (< Germanic; compare Old English hearpi ( g ) an to harp)

—Related forms
ar·peg·gi·at·ed, ar·peg·gi·oed, adjective

rpeggiated accompaniment

When the strings are more in the background, there are many ways in which they can add interest to the track without becoming too dominant.

The use of a repetitive arpeggiated accompaniment is one such technique - what this means is that the strings can oscillate between the various notes of the arpeggio (for example if the chord is in G major, the first violins could play G,B and D in rapid succession), then the second violins and violas could simultaneously add moving parts, using the other two notes of the same chord. The cello often adds stability to the other parts, by providing a more static line.

I'm sorry to add yet another answer, but none of those given so far works in all your examples.

In example (1), "arpegiado continuo", "arpegiado" is a noun, whereas in examples (2) and (3) it is an adjective. Accordingly it will be treated differently. In (1), "arpegiado" means a succession of arpeggios, and I think the correct translation is the obvious one: continuous arpeggios. The expression "arpegiado continuado" is used in the Spanish version of Robert Gualdin's Harmonic Practice in Tonal Music, applied to the first (C major) prelude in Book I of Bach's Well-Tempered Clavier, which consists entirely of a succession of arpeggios:
"Aunque la sensación de una verdadera melodía se ve debilitada por el arpegiado continuo, tendemos a escuchar las notas superiores de los arpegios como la línea melódica principal."
http://books.google.es/books?id=Kyeq_AsM7a0C&pg=PA73&lpg=PA7...

"Continuous arpeggios" is a standard expression for this, as for example here, in David Boyden's History of Violin Playing:
"Leopold Mozart seems to distinguish the style of breaking single chords from the style of continuous arpeggios"
http://www.google.es/search?hl=en&source=hp&biw=991&bih=541&...

What of "sustained arpeggio"? In the singular, it properly denotes an arpeggiated (broken) chord (that is, one in which the notes of the chord are played in succession, normally ascending, rather than simultaneously), in which the notes are held or sustained rather than released, so that by the end the whole chord is sounding. You can here one here: http://www.soundsnap.com/node/77238 . This is an effect commonly used on the organ, and a famous example is the ascending diminished seventh sustained arpeggio near the beginning of Bach's Toccata in D Minor for organ.
Although the expression "sustained arpeggios", in the plural, is sometimes used in the sense of "continuous arpeggios" (that is, a prolonged or sustained succession of arpeggios), I think this usage is confusing and should be avoided, since "sustain" properly means the continued sounding of particular notes. Clearly "arpegiado continuo" cannot mean a sustained arpeggio in the strict sense.

In example (2), both "arpeggio accompaniment" and "arpeggiated accompaniment" would be perfectly correct. They are really two ways of saying the same thing; an accompaniment consisting of arpeggios or an accompaniment which is arpeggiated as opposed to chordal.

In example (3), "arpeggiated" fits well, though you could also treat "arpegiados" as a noun and put "arpeggios".

"broken chord" works well as a noun and an adjective ("broken-chord accompaniment") and it sounds very natural in English.

Examples of scores with broken chords:
http://www.humanities.mcmaster.ca/~mus701/macmacvol2/nb/nbro...

an expressive, dreamy melody over broken-chord accompaniment.
http://www.chopinmusic.net/works/nocturnes/

I agree with Jenni that "sustained arpeggio" is what you should use in your first example.