Collection of maps created by (PG) ATROCITUS

"It is an ill-omened place, my lord. Cursed, they say, a fount of witches and other foulness. A chalice of corruption, haunted by a dead sun. They say it is but a matter of time before the stars align and the entire place is torn asunder by Daemons. Of course, they say that about a great many places. But in this case, master, the Tarot indicates it is actually true."
— Diviner Adept Harpious Mundis

"The Calixis Sector is a sector of the Milky Way Galaxy that serves as the setting for the Warhammer 40,000: Dark Heresy role-playing game, which focuses on the actions of Imperial Inquisitors and their chosen Acolytes and Throne Agents. The Calixis Sector is an Imperial sector located in the Segmentum Obscurus on the northern edge of the known galaxy, near the Halo Stars and the Eye of Terror. To the trailing edge of the galaxy, the Calixis Sector is bordered by the hazardous territories of the Fydae Great Cloud and to spinward by the Scarus Sector. Bordering to coreward, its immediate neighbour is the Ixaniad Sector. To rimward lie the contested and unregulated Imperial frontiers of the Halo Stars where humans and xenos mix in the quest for power and profit in the infamous Koronus Expanse. Conquered by Lord Militant Golgenna Angevin for the Imperium of Man almost two thousand standard years ago in the 39th Millennium during what became known as the Angevin Crusade, the Calixis Sector contains many heavily populated and important worlds, though it lies a great distance from the Imperium's core sectors. The sector's first Imperial Sector Governor was Drusus, one of Angevin’s most capable generals, a man now revered as a Saint of the Imperial Cult.

This territory represents a vulnerable fraction of the Imperium, far from the millions-strong armies and mighty battlefleets that protect its most ancient and important worlds and defend its war-torn frontiers. The fate of the sector is tainted with disturbing prophecies and haunted by an inexplicable evil. Within its ill-portended bounds there are countless threats to keep the Adepts of the Imperium stretched beyond capacity. It is up to a few extraordinary individuals to save the sector from being consumed by a dark future of corruption and suffering.

The Calixis Sector has many heavily populated and important worlds, but it lies a great distance from the Imperium’s heartland and, like so much of the Imperium of Man, it must ultimately fend for itself. Like all Imperial territories, the Calixis Sector is at risk from the chronic dangers facing humanity: war, mutation, xenos activity, the mark of Chaos, and so on. However, a singular threat lurks somewhere in the Calixis Sector, a mysterious, prophesied doom that has drawn the particular scrutiny of the Inquisition to this group of worlds. This enigmatic threat, the Hereticus Tenebrae, or the Tyrant Star as it is known, is something the forces of the Inquisition most fervently wish to uncover, to comprehend and to destroy, before it is too late for the people of the Calixis Sector--and perhaps all of Mankind.

The hive world of Scintilla, situated in the Golgenna Reach sub-sector, is the capital of the Calixis Sector. Along with the hellish mining world Sepheris Secundus and the war-torn planet Iocanthos, it forms a triumvirate of worlds essential for the sector’s survival. The most powerful man in the Calixis Sector is officially Sector Governor Marius Hax, who rules in the name of the Adeptus Terra from the Lucid Palace on Scintilla. However, the Calixian Conclave, led by Lord Inquisitor Caidin, is the true ultimate authority in the sector, a clandestine and all-powerful presence behind the visible emblems and figureheads of Imperial power. No one has the power to gainsay the word of the Inquisition. Other important Imperial servants are Lord Inquisitor Anton Zerbe of the Calixian Tyrantine Cabal, Cardinal Ignato of the Adeptus Ministorum, Lord Marshal Goreman of the Adeptus Arbites, Senior Astropath Xiao and Canoness Goneril of the Adepta Sororitas. The power of the Imperial Adepta, however, is rivalled by the Great Houses, the noble families and Calixian corporations, which maintain a presence across the sector. Even the minor noble houses, those whose influence is limited to a single world, hold a great deal of power over ordinary citizens."

(Link: Departmento Cartographicae Map of the Calixis Sector of the Segmentum Obscurus)
http://vignette2.wikia.nocookie.net/warhammer40k/images/d/dc/Calixis-map.jpg/revision/latest/scale-to-width-down/2000?cb=20101223092842