The outburst decay of the low magnetic field magnetar SWIFT J1822.3−1606: phase-resolved analysis and evidence for a variable cyclotron feature

We study the timing and spectral properties of the low-magnetic field, transient magnetar SWIFT J1822.3−1606 as it approached quiescence. We coherently phase-connect the observations over a time-span of ∼500 d since the discovery of SWIFT J1822.3−1606 following the Swift-Burst Alert Telescope (BAT) trigger on 2011 July 14, and carried out a detailed pulse phase spectroscopy along the outburst decay. We follow the spectral evolution of different pulse phase intervals and find a phase and energy-variable spectral feature, which we interpret as proton cyclotron resonant scattering of soft photon from currents circulating in a strong (≳1014 G) small-scale component of the magnetic field near the neutron star surface, superimposed to the much weaker (∼3 × 1013 G) magnetic field. We discuss also the implications of the pulse-resolved spectral analysis for the emission regions on the surface of the cooling magnetar.

Rockingham County, New Hampshire, 1857 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of Rockingham Co., New Hampshire, by actual surveys by J. Chace, Junr. It was published by Smith and Coffin in 1857. Scale [ca 1:15,840]. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the New Hampshire State Plane coordinate system (NAD 1983 in Feet) (Fipszone 2800). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town boundaries, and more. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Sullivan County, New Hampshire, 1860 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Topographical map of the county of Sullivan New-Hampshire, from surveys under the direction of H. F. Walling. It was published by Smith and Morley in 1860. Scale 1:40,000. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the New Hampshire State Plane coordinate system (NAD 1983 in Feet) (Fipszone 2800). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Essex County, Massachusetts, 1856 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of Essex County, Massachusetts : based upon the trigonometrical survey of the state the details, from actual surveys under the direction of H.F. Walling, superintendent of state map ; engd. by Geo. Worley & Wm. Bracher. It was published by Smith and Morley in 1856. Scale [ca. 1:50,000]. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Franklin County, Massachusetts, 1858 (Image 1 of 3) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of Franklin County, Massachusetts : based upon the trigonometrical survey of the state, the details from actual surveys under the direction of H.F. Walling, supt. of the state map. It was published by Smith & Ingraham in 1858. Scale [ca. 1:47,520]. This layer is image 1 of 3 total images, representing the northwest portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Franklin County, Massachusetts, 1858 (Image 3 of 3) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of Franklin County, Massachusetts : based upon the trigonometrical survey of the state, the details from actual surveys under the direction of H.F. Walling, supt. of the state map. It was published by Smith & Ingraham in 1858. Scale [ca. 1:47,520]. This layer is image 3 of 3 total images, representing the northeast portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Norfolk County, Massachusetts, 1858 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of the county of Norfolk, Massachusetts, based upon the details of the trigonometrical survey of the state; the details from actual surveys under the direction of Henry F. Walling. Supt. of the state map. It was published by Smith & Bumstead in 1858. Scale [ca. 1:40,000]. This layer is image 3 of 4 total images, representing the southeast portion of the four sheet source map. This image is georeferenced to the inset map entitled: Roxbury with portions of Dorchester, W. Roxbury &c. Scale 1:12,672.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Windham County, Connecticut, 1856 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Map of Windham County, Connecticut, from actual survey by E.P. Gerrish, W.C. Eaton & D.S. & H.C. Osborn, 1855; lith by W.H. Rease. It was published by E.M. Woodford in 1856. Scale [ca. 1:42,240]. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Connecticut State Plane coordinate system (NAD 1983 in Feet) (Fipszone 0600). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of New England from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates, scales, and map purposes.

Rock map of the Yellow River (Huang He) expedition, China, 1925-1927 : Sheet 3

This layer is part of a set of georeferenced, raster images of the manuscript, paper map set entitled: Ch'ing-Hai upper Yellow River expedition : Rock and Simpson, 1925-27, [cartography by J.F. Rock]. Scale 1:250,000. This layer image is of Sheet III [of 10] covering a portion of the Yellow River (Huang He) region in eastern Qinghai Sheng and southern Gansu Sheng, China. The map set details the route and surrounding environs of the Arnold Arboretum's "Western China" expedition led by Joseph Rock, 1924-1927. The set covers a portion of the Yellow River (Huang He) region in south central China (Qinghai, Gansu, and Sichuan shengs (a portion of historic Tibet)). It shows features, labeled variously in English, Chinese, Wade-Giles transliteration, and Tibetan, including: rivers, streams, lakes, mountains, gorges, valleys, plateaus, plains, cities, towns, villages, provincial capitals, county seats, passes, monasteries, ruin sites, native tribe locations, and more. Relief is shown by hachures, spot heights, and landform drawings. The original manuscript map set is part of the Harvard College Library, Harvard Map Collection. "Joseph Rock traced his travels for the [Arnold] Arboretum's [Western China] 1924-1927 expedition in a colorful, hand-drawn map entitled 'Ch'ing-Hai upper Yellow River expedition.' The pen-and-ink drawing was made on ten sheets that when joined form a single, irregularly-shaped map, approximately six by eight feet in size. The individual sheets are numbered, using roman numerals; on sheet VII is a second title, 'Choni Territory, Upper and Lower T'ieh-Pu country and route to Sung-Pan, J. F. Rock, 1925-1927.' Topographical and other features are identified using a combination of English, Chinese characters, Wade-Giles transliterations and Tibetan script. Rock's attractive cursive style and use of hachures, spot heights, and landform drawings to depict relief add character to the map." -- Text from the Arnold Arboretum Web site.