A Chandra image of the central X-ray source RX J0007.0+7303 in the supernova remnant CTA 1 reveals a point source , a compact nebula , and a bent jet , all of which are characteristic of energetic , rotation-powered pulsars .
Using the MDM 2.4m telescope we obtain upper limits in the optical at the position of the point source , ( J2000 ) 00 ^ { h } 07 ^ { m } 01. ^ { s } 56 , +73 ^ { \circ } 03 ^ { \prime } 08. ^ { \prime \prime } 1 , determined to an accuracy of 0. ^ { \prime \prime } 1 , of B > 25.4 , V > 24.8 , R > 25.1 , and I > 23.7 ; these correspond to an X-ray-to-optical flux ratio \gtrsim 100 .
Neither a VLA image at 1425 MHz , nor a deep pulsar search at 820 MHz using the NRAO Green Bank Telescope , reveal a radio pulsar counterpart to an equivalent luminosity limit at 1400 MHz of 0.02 mJy kpc ^ { 2 } , which is equal to the lowest luminosity known for any radio pulsar .
The Chandra point source accounts for \approx 30 \% of the flux of RX J0007.0+7303 , while its compact nebula plus jet comprise \approx 70 \% .
The X-ray spectrum of the point source is fitted with a power-law plus blackbody model with \Gamma = 1.6 \pm 0.6 , kT _ { \infty } = 0.13 \pm 0.05 keV , and R _ { \infty } = 0.37 km , values typical of a young pulsar .
An upper limit of T ^ { \infty } _ { e } < 6.6 \times 10 ^ { 5 } K to the effective temperature of the entire neutron star surface is derived , which is one of the most constraining data points on cooling models .
The 0.5–10 keV luminosity of RX J0007.0+7303 is \approx 4 \times 10 ^ { 31 } ( d / 1.4 { kpc } ) ^ { 2 } ergs s ^ { -1 } , but the larger ( \sim 18 ^ { \prime } diameter ) synchrotron nebula in which it is embedded is two orders of magnitude more luminous .
These properties allow us to estimate , albeit crudely , that the spin-down luminosity of the underlying pulsar is in the range 10 ^ { 36 } -10 ^ { 37 } ergs s ^ { -1 } , and support the identification of the high-energy \gamma -ray source 3EG J0010+7309 as a pulsar even though its spin parameters have not yet been determined .